This study aimed: 1) to develop an application system for analysis of Fairy Mushroom or Phoenix Oyster Mushroom cultivation investment and 2) to study the satisfaction of the users of the application for investment analysis, mushroom cultivation. The population of the study was 68 Fairy Mushroom cultivators in Nakhon Pathom. Then 30 of the Fairy Mushroom cultivators in Nakhon Pathom were selected to be the samples of the study by purposive sampling.  The research instruments used consisted of the quality evaluation questionnaire of the investment analysis of Fairy Mushroom cultivation and the satisfaction survey of the samples using the developed application. The statistics used for data analysis were percentage, mean, and standard deviation.The results showed that the quality evaluation result of the investment analysisof Fairy Mushroom cultivation was at a good level ( x = 4.96, S.D. = 0.21), and the satisfaction result of the samples toward the application was at an excellent level ( x = 4.63, S.D. = 0.28). Users of the application can use their knowledge to generate income, analyze and make decisions, and know the value of their mushroom investment.