EXHIBIT 31.1

CERTIFICATION OF CHIEF
EXECUTIVE OFFICER

CERTIFICATION PURSUANT
TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Robert L. Demorest, certify that:

|1. |  | I
have reviewed this Quarterly Report on Form 10-Q of MOCON, Inc.;
|-- |  | ------------------------------------------------------------------

|2. |  | Based
on my knowledge, this report does not contain any untrue statement of a
          material fact or omit to state a material fact necessary to make the statements
          made, in light of the circumstances under which such statements were made, not
          misleading with respect to the period covered by this report;
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|3. |  | Based
on my knowledge, the financial statements, and other financial information
          included in this report, fairly present in all material respects the financial
          condition, results of operations and cash flows of the registrant as of, and
          for, the periods presented in this report;
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|4. |  | The
registrants other certifying officer(s) and I are responsible for
          establishing and maintaining disclosure controls and procedures (as defined in
          Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | a) |  | Designed
such disclosure controls and procedures, or caused such disclosure
                    controls and procedures to be designed under our supervision, to
ensure that                     material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those
entities, particularly during the period in which this report is being prepared;
| | -- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | b) |  | Evaluated
the effectiveness of the registrants disclosure controls and
               procedures and presented in this report our conclusions about the
               effectiveness of the disclosure controls and procedures, as of the end of
the period covered by this report based on such evaluation; and
| | -- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | c) |  | Disclosed
in this report any change in the registrants internal control                over
financial reporting that occurred during the registrants most
               recent fiscal quarter that has materially affected, or is reasonably
likely to materially affect, the registrants internal control over financial
reporting; and
| | -- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|5. | The registrants other certifying officer(s) and I have disclosed, based on
          our most recent evaluation of internal control over financial reporting, to the
          registrants auditors and the audit committee of registrants Board of
          Directors (or persons performing the equivalent functions):
|-- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | a) |  | All
significant deficiencies and material weaknesses in the design or operation
               of internal control over a financial reporting which are reasonably likely
to                adversely affect the registrants ability to record, process,
summarize and report financial information; and
| | -- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | b) |  | Any
fraud, whether or not material, that involves management or other employees
               who have a significant role in the registrants internal control
over                financial reporting.
| | -- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Date:   November 15, 2004

/s/   Robert L. Demorest

---

---