The strain gauge holder 1 includes a holder body 10 on a side surface of a pipe 3, a gauge pressing member 21 for pressing a strain gauge 2 against the side surface of the pipe, and a feed mechanism for giving a pressing force to the gauge pressing member. The guide grooves 12 guide the gauge pressing members. The feed mechanism feeds the gauge pressing member in the guide groove to press the strain gauge 2 against the side surface of the pipe 3. The feed mechanism includes cylindrical portion 32a, bushing 32, and feed screw 31. Each of the feed screws 31 threadedly inserted into the bushing mounted on the holder body is threadedly inserted to feed the gauge pressing member.