<PAGE>   1

                                      1998
================================================================================
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 10-QSB


(Mark One)
[X]   Quarterly Report Pursuant to Section 13 or 15(d) of the Securities
      Exchange Act of 1934 
      For the quarterly period ended March 31, 1998.
                                       or
[ ]   Transition Report Pursuant to Section 13 or 15(d) of the Securities 
      Exchange Act of 1934
      For the transition period from ______________ to ______________________

Commission file number:  0-12742


                                SPIRE CORPORATION
--------------------------------------------------------------------------------
        (Exact Name of Small Business Issuer as Specified in Its Charter)



         Massachusetts                                   04-2457335
--------------------------------------------------------------------------------
(State or Other Jurisdiction of             (I.R.S. Employer Identification No.)
Incorporation or Organization)

One Patriots Park, Bedford, Massachusetts                01730-2396
--------------------------------------------------------------------------------
(Address of Principal Executive Offices)                 (Zip Code)


                                  781-275-6000
--------------------------------------------------------------------------------
                (Issuer's Telephone Number, Including Area Code)


     Check whether the issuer: (1) filed all reports required to be filed by
Section 13 or 15(d) of the Exchange Act during the past 12 months (or for such
shorter period that the registrant was required to file such reports); and (2)
has been subject to such filing requirements for the past 90 days.  Yes X  No
                                                                       ---   ---

     State the number of shares outstanding of each of the issuer's classes of
common equity, as of the latest practicable date. There were 3,241,716
outstanding shares of the issuer's only class of common equity, Common Stock,
$.01 par value, on April 30, 1998.


     Transitional Small Business Disclosure Format (Check One):     Yes    No X
                                                                       ---   ---

<PAGE>   2
                                SPIRE CORPORATION
                                      INDEX



                                                                     Page Number
                                                                     -----------
PART I - FINANCIAL INFORMATION

    Condensed Consolidated Balance Sheets at                               3
    March 31,1998 (unaudited) and December 31, 1997

    Condensed Consolidated Statements of Operations                        4
    For the Three Months Ended March 31, 1998 and 1997 (unaudited)

    Condensed Consolidated Statements of Cash Flows                        5
    For the Three Months Ended March 31, 1998 and 1997 (unaudited)

    Notes to Condensed Consolidated Financial Statements                   6

    Management's Discussion and Analysis of Financial                    7 - 9
    Condition and Results of Operations


PART II - OTHER INFORMATION

    Item 1.  Legal Proceedings                                            10

    Item 6.  Exhibits and Reports on Form 8-K                             10




                                       2
<PAGE>   3

                        SPIRE CORPORATION AND SUBSIDIARY
                      CONDENSED CONSOLIDATED BALANCE SHEETS

<TABLE>
<CAPTION>
                                                                                   MARCH 31,      DECEMBER 31,
                                                                                      1998           1997
                                                                                  -----------     -----------
<S>                                                                               <C>             <C>        
                                           ASSETS
CURRENT ASSETS
  Cash and cash equivalents                                                       $   691,644     $ 1,695,727
  Accounts receivable, trade:
    Amounts billed                                                                  3,478,098       3,012,701
    Retainage                                                                          73,392          69,772
    Unbilled costs                                                                    523,807         621,760
                                                                                  -----------     -----------
                                                                                    4,075,297       3,704,233
    Less allowance for doubtful accounts                                               40,000          40,000
                                                                                  -----------     -----------
      Net accounts receivable                                                       4,035,297       3,664,233
                                                                                  -----------     -----------

  Inventories (Note 2)                                                              1,675,830         988,580
  Deferred income taxes (Note 3)                                                      300,000         300,000
  Prepaid expenses and other current assets                                           644,812         501,650
                                                                                  -----------     -----------
      Total current assets                                                          7,347,583       7,150,190
                                                                                  -----------     -----------

Property and equipment                                                             24,382,076      24,015,445
  Less accumulated depreciation and amortization                                   19,464,148      19,242,437
                                                                                  -----------     -----------
      Net property and equipment                                                    4,917,928       4,773,008
                                                                                  -----------     -----------

Computer software costs (less accumulated amortization, $814,017 in 1998
  and $810,466 in 1997)                                                                47,585          51,135
Patents (less accumulated amortization, $556,227 in 1998 and $542,344 in 1997)        265,338         274,810
Other assets                                                                           17,771          19,679
                                                                                  -----------     -----------
                                                                                      330,694         345,624
                                                                                  -----------     -----------
                                                                                  $12,596,205     $12,268,822
                                                                                  ===========     ===========
                      LIABILITIES AND STOCKHOLDERS' EQUITY
CURRENT LIABILITIES
  Accounts payable                                                                $   888,461     $   903,581
  Accrued liabilities                                                                 843,021         859,093
  Advances on contracts in progress                                                   636,994         410,370
                                                                                  -----------     -----------
      Total current liabilities                                                     2,368,476       2,173,044
                                                                                  -----------     -----------

COMMITMENTS

STOCKHOLDERS' EQUITY
  Common stock, $.01 par value; shares authorized 20,000,000;
    issued 3,788,876 shares in 1998 and 3,757,082 shares in 1997                       37,889          37,571
  Additional paid-in capital                                                        9,759,942       9,645,468
  Retained earnings                                                                 1,649,586       1,632,427
                                                                                  -----------     -----------
                                                                                   11,447,417      11,315,466
  Treasury stock at cost, 552,160 shares                                           (1,219,688)     (1,219,688)
                                                                                  -----------     -----------
      Total stockholders' equity                                                   10,227,729      10,095,778
                                                                                  -----------     -----------
                                                                                  $12,596,205     $12,268,822
                                                                                  ===========     ===========
</TABLE>

     See accompanying notes to condensed consolidated financial statements.


                                       3
<PAGE>   4

                        SPIRE CORPORATION AND SUBSIDIARY
                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

<TABLE>
<CAPTION>
                                                                THREE MONTHS ENDED MARCH 31,
                                                                ----------------------------
                                                                   1998             1997
                                                                ----------       ----------
                                                                              
<S>                                                             <C>              <C>       
NET SALES AND REVENUES                                                        
  Contract research, service and license revenues               $3,115,886       $3,133,491
  Sales of manufacturing equipment                               1,326,640        1,317,208
                                                                ----------       ----------
    Total sales and revenues                                     4,442,526        4,450,699
                                                                ----------       ----------
                                                                              
COSTS AND EXPENSES                                                            
  Cost of contract research, services and licenses               2,207,178        2,074,106
  Cost of manufacturing equipment                                  803,761          856,108
  Selling, general and administrative expenses                   1,417,765        1,373,808
                                                                ----------       ----------
    Total costs and expenses                                     4,428,704        4,304,022
                                                                ----------       ----------
                                                                              
EARNINGS FROM OPERATIONS                                            13,822          146,677
                                                                              
Interest income, net                                                12,337            3,617
                                                                ----------       ----------
                                                                              
Earnings before income taxes                                        26,159          150,294
                                                                              
Income tax expense                                                   9,000               --
                                                                ----------       ----------
                                                                              
NET EARNINGS                                                    $   17,159       $  150,294
                                                                ==========       ==========
                                                                              
EARNINGS PER SHARE OF COMMON STOCK - BASIC                      $     0.01       $     0.05
                                                                ==========       ==========
                                                                              
EARNINGS PER SHARE OF COMMON STOCK - DILUTED                    $     0.01       $     0.05
                                                                ==========       ==========
                                                                              
Weighted average number of common shares outstanding - basic     3,216,869        3,020,025
                                                                ==========       ==========
                                                                              
Weighted average number of common and  common equivalent                      
  shares outstanding - diluted                                   3,350,910        3,020,025
                                                                ==========       ==========
</TABLE>
                                                                           
     See accompanying notes to condensed consolidated financial statements.


                                       4
<PAGE>   5

                        SPIRE CORPORATION AND SUBSIDIARY
                 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

<TABLE>
<CAPTION>
                                                                    THREE MONTHS ENDED MARCH 31,
                                                                    ----------------------------
                                                                        1998              1997
                                                                    -----------        ---------
<S>                                                                 <C>                <C>      
 Cash flows from operating activities:
  Net earnings                                                      $    17,159        $ 150,294
  Adjustments to reconcile net earnings to net
   cash used in operating activities:
     Depreciation and amortization                                      239,144          309,250
     Changes in assets and liabilities:
       Accounts receivable                                             (371,064)        (505,986)
       Inventories                                                     (687,250)        (932,999)
       Prepaid expenses and other current assets                       (143,162)        (137,359)
       Accounts payable and accrued liabilities                         (31,192)          24,997
       Advances on contracts in progress                                226,624          311,197
                                                                    -----------        ---------
         Net cash used in operating activities                         (749,741)        (780,606)
                                                                    -----------        ---------

Cash flows from investing activities:
  Additions to property and equipment                                  (366,631)        (135,435)
  Increase in patent costs                                               (4,411)            (315)
  Increase in software production costs                                      --          (34,229)
  Other assets                                                            1,908          219,292
                                                                    -----------        ---------
         Net cash provided by (used in) investing activities           (369,134)          49,313
                                                                    -----------        ---------

Cash flows from financing activities:
  Exercise of stock options                                             114,792               --
  Repurchase of common stock                                                 --          (20,625)
                                                                    -----------        ---------
         Net cash provided by (used in) financing activities            114,792          (20,625)
                                                                    -----------        ---------

Net decrease in cash and cash equivalents                            (1,004,083)        (751,918)

Cash and cash equivalents, beginning of period                        1,695,727          970,997
                                                                    ===========        =========
Cash and cash equivalents, end of period                            $   691,644        $ 219,079
                                                                    ===========        =========

Supplemental disclosures of cash flow information:
     Cash paid during the year for:
       Interest expense                                             $       723        $      --
                                                                    ===========        =========
       Income taxes                                                 $    44,400        $      -- 
                                                                    ===========        =========
</TABLE>

     See accompanying notes to condensed consolidated financial statements.


                                       5
<PAGE>   6

                        SPIRE CORPORATION AND SUBSIDIARY
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 March 31, 1998


(1)  INTERIM FINANCIAL STATEMENTS

          In the opinion of management, the accompanying unaudited condensed
     consolidated financial statements contain all adjustments necessary to
     fairly present the Company's financial position as of March 31, 1998 and
     the results of operations and changes in cash flows for the three months
     ended March 31, 1998 and 1997. The results of operations for the three
     months ended March 31, 1998 are not necessarily indicative of the results
     to be expected for the fiscal year ending December 31, 1998.

          The accounting policies followed by the Company are set forth in Note
     2 to the Company's consolidated financial statements in its annual report
     on Form 10-KSB for the year ended December 31, 1997.

          The financial statements, with the exception of the December 31, 1997
     balance sheet, are unaudited and have not been examined by independent
     public accountants.


(2)  INVENTORIES

          Inventories consist of the following:

<TABLE>
<CAPTION>
                                       March 31,      December 31,
                                         1998             1997
                                      ----------      ------------
          <S>                         <C>               <C>     
          Raw materials               $  903,100        $736,930
          Work in process                772,730         251,650
                                      ----------        --------
                                      $1,675,830        $988,580
                                      ==========        ========
</TABLE>


                                 

                                       6
<PAGE>   7


ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS

OVERVIEW

     Spire develops, manufactures and markets highly-engineered photovoltaic
module manufacturing equipment and optoelectronic products and provides
biomedical processing services. Spire is the world's leader in the design and
manufacture of specialized equipment for the production of terrestrial
photovoltaic modules from solar cells, with its equipment installed in 136
factories and in 38 countries. The Company also offers certain optoelectronic
products and is continuing to develop additional advanced optoelectronic
products for telecommunications, biomedical and electronics applications,
including solar cells used to power satellites. Spire's value-added biomedical
processing services offer surface treatments to enhance the durability or the
antimicrobial characteristics of orthopedic and other medical devices.

     The Company's net sales and revenues for the quarter ended March 31, 1998
declined slightly, compared to the quarter ended March 31, 1997. The Company's
Optoelectronics business showed growth, our Photovoltaic equipment sales were
the same and Biomedical revenues showed some decline in net sales and revenues
compared to the first quarter of 1997.

RESULTS OF OPERATIONS

     The following table sets forth certain items as a percentage of net sales
and revenues for the periods presented:

<TABLE>
<CAPTION>
                                                         Three Months Ended March 31,
                                                         ----------------------------
                                                          1998                 1997
                                                         ------               -------

     <S>                                                 <C>                  <C>   
     Net sales and revenues                              100.0%               100.0%
     Cost of sales and revenues                           67.8                 65.8
                                                         -----                -----
     Gross profit                                         32.2                 34.2
     Selling, general and administrative expenses         31.9                 30.9
                                                         -----                -----
     Earnings from operations                              0.3                  3.3
     Earnings before income taxes                          0.6                  3.4
     Income tax expense                                    0.2                  0.0
                                                         -----                -----
     Net earnings                                          0.4%                 3.4%
                                                         =====                =====
</TABLE>

QUARTER ENDED MARCH 31, 1998 COMPARED TO QUARTER ENDED MARCH 31, 1997

Net Sales and Revenues

     Net sales and revenues decreased $8,000 or less than 1% for the quarter
ended March 31, 1998 to $4,443,000, compared to $4,451,000 for the quarter ended
March 31, 1997. Contract research, service and license revenues decreased
$18,000 or 1% to $3,116,000 for the quarter ended March 31, 1998 compared to
$3,134,000 for 1997. Manufacturing equipment sales increased $10,000 or 1% to
$1,327,000 for 1998, compared to $1,317,000 for 1997. The following table
categorizes the Company's net sales and revenues for the periods presented:

<TABLE>
<CAPTION>
                                                            Three Months Ended March 31,
                                                       --------------------------------------
                                                         1998            1997        Change
                                                       ----------     ----------    ---------

     <S>                                               <C>            <C>              <C> 
     Contract research, service and license revenues   $3,116,000     $3,134,000       (1%)
     Manufacturing equipment sales                      1,327,000      1,317,000        1%
                                                       ----------     ----------
     Net sales and revenues                            $4,443,000     $4,451,000      (<1%)
                                                       ==========     ==========
</TABLE>

                                       7
<PAGE>   8

Cost of Sales and Revenues

     The cost of sales and revenues increased $81,000 to $3,011,000, and
increased to 68% of net sales and revenues, for the quarter ended March 31,
1998, compared to $2,930,000 or 66% of net sales and revenues for the quarter
ended March 31, 1997.

     The cost of contract research, service and license revenues increased
$133,000 to $2,207,000, and increased to 71% of related revenues, for the
quarter ended March 31, 1998, compared to $2,074,000 or 66% of related revenues
for the quarter ended March 31, 1997. Cost of manufacturing equipment sales
decreased $52,000 to $804,000, and decreased to 61% of related sales, for the
quarter ended March 31, 1998, compared to $856,000 or 65% of related sales, for
the quarter ended March 31, 1997. The increase in total cost of sales and
revenues as a percentage of related sales and revenues is due to product mix,
and increased product development cost.

     The following table categorizes the Company's cost of sales and revenues
for the periods presented, stated in dollars and as a percentage of related
sales and revenues:

<TABLE>
<CAPTION>
                                                             Three Months Ended March 31,
                                                        --------------------------------------
                                                          1998          %        1997       %
                                                        ----------     ---    ----------   ---

     <S>                                                <C>            <C>    <C>          <C>
     Contract research, service and license revenues    $2,207,000     71%    $2,074,000   66%
     Manufacturing equipment sales                         804,000     61%       856,000   65%
                                                        ----------            ----------
     Total cost of sales and revenues                   $3,011,000     68%    $2,930,000   66%
                                                        ==========            ==========
</TABLE>

Selling, General and Administrative Expenses

     Selling, general and administrative expenses for the quarter ended March
31, 1998 increased $44,000 to $1,418,000, and increased to 32% of sales and
revenues, compared to $1,374,000 or 31% of sales and revenues for the quarter
ended March 31, 1997. Selling, general and administrative expenses increased due
to increases in sales and marketing and legal costs.

Depreciation and Amortization Expenses

     Depreciation and amortization expenses for the quarter ended March 31, 1998
decreased $70,000 or 23% to $239,000, compared to $309,000 for the quarter ended
March 31, 1997. Capital expenditures increased $231,000 or 171% to $367,000 for
the quarter ended March 31, 1998, compared to $136,000 for the quarter ended
March 31, 1997.

Interest

     The Company earned $13,000 in interest income for the quarter ended March
31, 1998, compared to $2,000 for the quarter ended March 31, 1997. The Company
incurred insignificant interest expense in both periods.

Income Taxes

     The Company recorded income tax expense of $9,000 for the quarter ended
March 31, 1998 and no income tax expense for the quarter ended March 31, 1997.
At March 31, 1998, the Company had gross deferred tax assets of $300,000, which
represents the amount of tax benefits of existing deductible temporary
differences or carryforwards that are more likely than not to be realized
through the generation of sufficient future taxable income within the
carryforward period.

Net Earnings

     The Company reported net earnings for the quarter ended March 31, 1998 of
$17,000, compared to net earnings of $150,000 for the quarter ended March 31,
1997. The decline in the Company's profitability resulted in large part from
flat net sales and revenues when compared with the prior period, and an increase
in product development costs, sales and marketing expenses and legal costs in
the first quarter of 1998. 



                                       8
<PAGE>   9

LIQUIDITY AND CAPITAL RESOURCES

     The Company has been able to fund its liquidity requirements using cash
from operations and available lines of credit. On April 4, 1997, the Company
amended and extended its revolving credit agreement with Silicon Valley Bank.
This agreement provides for a $2 million revolving credit facility, based upon
eligible accounts receivable requirements. This line of credit has been
established to provide the Company with resources for general working capital
purposes and Standby Letter of Credit Guarantees for foreign customers. The line
is secured by all assets of the Company. Interest on the line is at the Bank's
prime rate plus one-half of one percent. The line contains covenants including
provisions relating to profitability and net worth. As of March 31, 1998, the
Company had no outstanding debt under this revolving credit facility, which is
in the process of being renewed under the existing terms and conditions. The
Company has also entered into a $1 million equipment leasing line with Silicon
Valley Bank.

     The Company believes it has sufficient resources to finance its current
operations for the foreseeable future through working capital, its existing line
of credit and available lease arrangements. Cash and cash equivalents decreased
$1,004,000, to $692,000 at March 31, 1998, from $1,696,000 at December 31, 1997.
This decrease was primarily due to the Company's funding a $687,000 increase in
its raw materials and in process inventories from December 31, 1997 to March 31,
1998, and first quarter 1998 capital purchases of $367,000. To date there are no
material commitments by the Company for capital expenditures. At March 31, 1998,
the Company's retained earnings were $1,650,000, compared to retained earnings
of $1,632,000 as of December 31, 1997. Working capital as of March 31, 1998
increased less than 1% to $4,979,000, compared to $4,977,000 as of December 31,
1997.

RECENT ACCOUNTING PRONOUNCEMENTS

     In December 1997, the Company adopted Financial Accounting Standards Board
Statement No. 128, "Earnings per Share." (SFAS 128). All previously reported net
earnings per share data have been restated to conform to the provisions of SFAS
No. 128. Under SFAS 128, basic earnings per share are computed by dividing net
earnings available to common stockholders by the weighted average number of
common shares outstanding for the period. Diluted earnings per share reflect the
maximum dilution that would have resulted from the assumed exercise and share
repurchase related to dilutive stock options and are computed by dividing net
earnings by the weighted average number of common shares and all dilutive
securities outstanding.

     In June 1997, the Financial Accounting Standards Board issued SFAS 130,
"Reporting Comprehensive Income," which establishes standards for reporting and
display of comprehensive income and its components in a full set of
general-purpose financial statements. Under this concept, all revenues,
expenses, gains and losses recognized during the period are included in income,
regardless of whether they are considered to be results of operations of the
period. The Company adopted SFAS 130 in March 1998, and it had no impact on the
Consolidated Financial Statements of the Company.

     In June 1997, the Financial Accounting Standards Board issued SFAS 131,
"Disclosures about Segments of an Enterprise and Related Information," which
establishes standards for the way that public business enterprises report
selected information about operating segments in annual financial statements and
requires that those enterprises report selected information about operating
segments in interim financial reports to stockholders. It also establishes
standards for related disclosures about products and services, geographic areas
and major customers. SFAS 131, which becomes effective for the Company in its
year ending December 31, 1998, is not expected to have a material impact on the
Company's results of operations. The Company is in the process of determining
the impact of SFAS 131 on its footnote disclosures.

     In March 1998, the American Institute of Certified Public Accountants
issued Statement of Position 98-1, "Accounting for the Costs of Computer
Software Developed or Obtained for Internal Use" (SOP 98-1), which establishes
guidelines for the accounting for the costs of all computer software developed
or obtained for internal use. SOP 98-1 is effective for the Company in 1999 and
is not expected to have a material effect on the Company's financial statements.

     THE FOREGOING STATEMENTS MAY INCLUDE FORWARD-LOOKING STATEMENTS SUBJECT TO
RISKS AND UNCERTAINTIES THAT COULD CAUSE ACTUAL RESULTS TO DIFFER MATERIALLY
FROM THOSE INDICATED IN THE FORWARD-LOOKING STATEMENTS. FACTORS THAT MIGHT CAUSE
SUCH A DIFFERENCE INCLUDE, BUT ARE NOT LIMITED TO, THOSE DISCUSSED OR REFERRED
TO IN THIS REPORT AND IN ITEM 6 OF THE ANNUAL REPORT ON FORM 10-KSB FOR THE YEAR
ENDED DECEMBER 31, 1997.



                                       9
<PAGE>   10

PART II - OTHER INFORMATION


ITEM 1.  LEGAL PROCEEDINGS

     On March 2, 1998 the Company received a letter from the Office of the
United States Attorney for the Eastern District of Virginia stating that it was
considering the commencement of a civil action concerning seven research
initiatives undertaken by the Company in the period from 1990 to the present.
The letter alleged that, in certain instances, the Company had failed to inform
the government of pending or previously submitted proposals for work the
government alleges was related to proposals which were funded. The Company is in
the process of reviewing the allegations, and gathering the information
necessary to respond. The Company is unable to determine at this time what
effect, if any, this matter will have on the Company's financial condition or
results of operations.


ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

A.   The following exhibits are filed herewith:

     11   Statement Regarding Computation of Per Share Earnings

     27   Financial Data Schedule

B.   During the quarter ended March 31, 1998, the Company filed no reports on
     Form 8-K.



                                       10
<PAGE>   11


                                   SIGNATURES


In accordance with the requirements of the Exchange Act, the registrant caused
this report to be signed on its behalf by the undersigned, thereunto duly
authorized.


                                    SPIRE CORPORATION
                                    (Registrant)

    14 May 1998                     By: /s/ Roger G. Little
-------------------                     ----------------------------------------
Date                                    Roger G. Little
                                        President, Chief Executive Officer and 
                                        Chairman of the Board


    14 May 1998                     By: /s/ Richard S. Gregorio
-------------------                     ----------------------------------------
Date                                    Richard S. Gregorio
                                        Vice President and Chief Financial 
                                        Officer, Treasurer, Clerk and
                                        Principal Accounting Officer


                                       11