Catfish is a fish that has quie a lot of mucus, the mucus itself is a medium for bacterial growth. So that the physical condition of dead catfish meat cannot last long at room emperature. Extremenly.Low.Frequency (ELF).magnetic.field.is.a wave spectrum.that has a low frequency of less.than 30 Hz and is classified.a. non-ionizing.radiation. The ELF magnetic field can be used in the food sector, because a magnetic.field.can.be.applied.to inactivate.pathogenic.microorganisms.that can cause perishable food ingredients. The value of pH (Potential Hydrogen) is one of he factors that can be used as a refrence o measure freshness in fish. This study aims to determine he effect of exposure to the ELF magnetic field on the freshness of cafish meat by reffering to is pH value. In this study there were 120 samples of catfish fillet meat, with the division of the control group. Where the experimental group was exposed to magnetic fields of 600μT and 1000 μT for 30 minuets, 60 minuets, and 90 muniets. Measurement of pH was measure using a pH meter. The.result.of.this.research.is that exposure to a magnetic field with an intensity of 600μT and 1000μT can inhibit the decrease in pH in catfish meat with the most effective dose of 1000μT for 90 minuets