A biological information detecting apparatus has an apparatus main body, a pair of biological signal detecting parts provided on the apparatus main body, a fixing part attached to the apparatus main body, holders provided to be slidable along a longitudinal direction of the fixing part, and joining parts configured to releasably join the pair of biological signal detecting parts to the respective holders. Each of the biological signal detecting parts has an electrode adapted to be in contact with a biological surface of a user's body. The fixing part is configured to fix the apparatus main body and the pair of biological signal detecting parts to the user's body.