To reduce the consuming time and labor for measurement, new desorbed gas measurement devices were developed. Measurement of gas content of some coal seams in Hokkaido were carried out by using those new devices. In this paper, measurement results are described. From the results, we may conclude as followings;
1) Measurement method of desorbed gas by using new devices could reduce the time and labor consuming for measurement.
2) The coal seam of the highest gas content is the Lower Seam of Mitsubishi Minami Oyubari Coal Mine and the value is 12.9cc/g. The lowest one is Noborikawa No.1 Coal Seam of Sorachi Coal Mine and the value is 0.33cc/g.
3) Generally, the gas content increases with the depth of borehole which is drilled for sample collection. But the gas content of some samples which were collected at the depth of 20m or 25m at Mitsui Ashibetsu Coal Mine were little. The main cause for decreasing the gas content can be related to the stress distribution around the roadway.
4) The gas content of coal seam depends on geological condition of the surrounding formation where samples are collected and quality of coal.