A Combined Cycle Power Plant uses large engine to produce electricity. In order to ensure plant optimization, reliability and safety that requires to shut down the engine for comprehensive maintenance program as manufacture’s recommendations. But during Inspection and Maintenance process, there are a lot of hazard might potentially of serious accident. Thus, this study aims to applied the Semi-Quantitative Risk Assessment by considering of 3 elements for determine risk score which are Hazard Severity Categories, Frequency of Incident and Probability of Hazard Categories. The hazard Categories of each task steps have risk rating higher than 5 must be subjected and analyzed together with statistics of Accident and Concern Reporting into the Heat Map format. The results of this study, there are 78 tasks of core activities which including 390 task steps. We have identified hazard among 52 categories that could be harmful to maintenance worker. The risk evaluation results shown high risk of Gas Turbine is 76 task steps, Steam Turbine is 10 task steps, Generator is 11 task steps, Commissioning is 15 task steps and Specific task is 23 task steps. The analyzing of Heat Map is showing 10 Risks Categories that must be determine STOP Work and additional defenses are required to reduce the risk to an acceptable or low level immediately. Therefore, the semi-qualitative risk assessment methodology is an effective tool to identify high risk and useful for making decision to do Risk Reduction Programs coverage to incident prevention of Inspection and Maintenance for Combined Cycle Power Plant.