eGovernment has been defined as an Information and Communication Technology (ICT) enabled route to good governance for citizen and business, employees and other governmental organizations. eGovernment is an evolutionary path that its effective implementation requires a comprehensive vision. For the employing eGovernment, first of all we need to know what its current and desirable position is. Then we can present a good plan for reaching the desirable position. This paper introduces a new heuristic model that could be used to measure eGovernment maturity called "eGovernment Maturity Model for Iran's Ministry of Commerce" (eGMMIMC). According to this model, maturity of an organization is equal to sum of subsidiaries, maturity. For deploying this model in the Iran's Ministry of Commerce, we developed a fuzzy system and measured eGovernment maturity. According to the results, eGovernment for Iran's Ministry of Commerce is in the lowest level entitled Readiness.