The objective of this research was to develop Crispy Fermented Mushroom (Name Het Krob) from fermented oyster-mushroom product. by studying the optimal of thickness, temperature and baking time, It was found that the optimum condition was Nham mushroom sheet thickness 1 mm. at the temperature of 120^๐C for 30 min as the highest crispness value of 9.5±2.12 and the highest liking score was 5.4±0.84. Measure the color It was found that the baking time increased, the L* and b* values tended to decrease, while the a* values tended to be higher. Therefore, it has a darker color. Water activity, pH, NaCl content and Na content were 0.31±0.01, 4.19±0.00, 2.73 g/100g, and 2,145.78±0.52 mg/g. Total count, yeast, mold and E. coli were analyzed and found that they passed the community product standard. And when studying the 30-day storage period for Nham Mushroom Crisps, it was found that the Nham Mushroom Crisps had decreased hardness and increased aw values, but were still within the community standard.