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                                                                    EXHIBIT 11.1
 
                            UNIT INSTRUMENTS, INC.
                       COMPUTATION OF EARNINGS PER SHARE

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                                                               Three Months Ended           Nine Months Ended      
                                                               ------------------           -----------------      

                                                             03/01/97      03/02/96        03/01/97      03/02/96 
                                                            ---------      --------        --------      -------- 
<S>                                                        <C>           <C>            <C>          <C>          
                                                                                                   
INCOME (LOSS) FROM                                                                                 
CONTINUING OPERATIONS                                      $ (900,000)   $1,484,000     $(3,456,000)   $3,168,000 
                                                           ----------    ----------     -----------    ---------- 
                                                                                                                  
NET INCOME (LOSS)                                          $ (900,000)   $1,484,000     $(3,456,000)   $5,372,000 
                                                           ==========    ==========     ===========    ========== 
                                                                                                                  
Earnings Per Share                                                                                                
------------------                                                                                 
                                                                                                                  
Weighted average number                                                                                           
of shares outstanding                                       4,370,325     4,079,859       4,378,529     4,147,929 
                                                                                                                  
Common share equivalents,                                                                                         
assuming exercise of stock                                                                                        
options and warrants                                              -0-       238,345             -0-       271,839 
                                                           ----------    ----------     -----------    ---------- 
                                                                                                                  
Average shares used in                                                                                            
computing earnings per share                                4,370,325     4,318,204       4,378,529     4,419,768 
                                                           ==========    ==========     ===========    ========== 
                                                                                                                  
Net income (loss) per share from                                                                                  
continuing operations                                      $    (0.21)   $     0.34     $     (0.79)   $     0.72 
                                                           ----------    ----------     -----------    ---------- 
                                                                                                                  
Net income (loss) per share                                $    (0.21)   $     0.34     $     (0.79)   $     1.21 
                                                           ==========    ==========     ===========    ========== 
                                                                                                   
                                                                                                                  
Earnings Per Share Assuming Full Dilution                                                                         
----------------------------------------                                                                          
                                                                                                   
Weighted average number                                                                                           
of shares outstanding                                       4,370,325     4,079,859       4,378,529     4,147,929 
                                                                                                   
Common share equivalents, assuming                                                                                
exercise of stock options and warrants                            -0-       238,345             -0-       271,839 
                                                           ----------    ----------     -----------    ---------- 
                                                                                                   
Average shares used in computing                                                                                  
earnings per share                                          4,370,325     4,318,204       4,378,529     4,419,768 
                                                           ==========    ==========     ===========    ========== 
                                                                                                   
Net income (loss) per share from                                                                                  
continuing operations                                      $    (0.21)   $     0.34     $     (0.79)   $     0.72 
                                                           ----------    ----------     -----------    ---------- 
                                                                                                                  
Net income (loss) per share                                $    (0.21)   $     0.34     $     (0.79)   $     1.21 
                                                           ==========    ==========     ===========    ==========  
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