***Juniata Valley Financial Corp.*****Exhibit 31.2 Rule 13a — 14(a)/15d — 14(a) Certification of Chief Financial Officer**I, JoAnn N. McMinn, certify that:1. I have reviewed this amended quarterly report on Form 10-Q/A of Juniata Valley Financial Corp.; 2. Based on my knowledge, this report does not contain any untrue statements of a material fact oromit to state amaterial fact necessary to make the statements made, in light of the circumstances under whichsuch statementswere 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 inthis report, fairlypresent in all material respects the financial condition, results of operations and cash flowsof the registrant as of,and for, the periods presented in this report;4. The registrant’s other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d -15(f) for the registrant and have: a) Designed such disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that material information relating tothe registrant, including its consolidated subsidiaries, is made known to us by others withinthose entities, particularly during the period in which this report is being prepared;  b) Designed such internal control over financial reporting, or caused such internal controlover financial reportingto be designed under our supervision, to provide reasonable assurance regarding thereliability of financialreporting and the preparation of financial statements for external purposes in accordancewith generallyaccepted accounting principles:  c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of the disclosure controls andprocedures, as of the end of the period covered by this report based on such evaluation; and  d) Disclosed in this report any change in the registrant’s internal control over financialreporting that occurredduring the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarterin the case of an annualreport) that has materially affected, or is reasonably likely to materially affect, theregistrant’s internal controlover financial reporting; and5. The registrant’s other certifying officer and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the registrant’s auditors and the auditcommittee of the registrant’s board of directors (or persons performing the equivalent functions): a) All significant deficiencies and material weaknesses in the design or operation ofinternal control over financialreporting 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 asignificant rolein the registrant’s internal control over financial reporting.     Date September 15, 2005            /s/ JoAnn N. McMinn    JoAnn N. McMinn, Chief Financial Officer  
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