The purpose of the research is to examine the effect of Extremely Low Frequency (ELF) magnetic field to pH and electrical conductivity in the wet fermentation process of liberica coffee with the addition of α-amylase. Type of the research is an experimental research with randomized subjects post test only control group design. There is seven treatments consist of control group and experimental group exposed to ELF magnetic field with 300 µT and 400 µT intensity variation and for 30, 60, and 90 minutes for long variations. For hours 24, 48, day 3, day 4, and day 5, can make data retrieval after fermentation process. The result explain is effect of Extremely Low Frequency (ELF) magnetic field to pH and electrical conductivity in the wet fermentation process of liberica coffee with the addition of α-amylase was take effect to indicated by the variation of the graph. The process ELF magnetic field with 400 µT intensity for 30 minutes most influential on pH of liberica coffee. Meanwhile, the process ELF magnetic field with 300 µT intensity for 30 and 90 minutes most influential on electrical conductivity of liberica coffee in the wet fermentation with the addition of α-amylase.