A biological information detecting device of the present invention, which detects the pulse of a user, includes a detecting section which outputs an observation signal detected based on a pulse wave of at least one observation site of the user and an acceleration measuring section which outputs a plurality of acceleration signals in each of a plurality of axial directions measured along with the users movement. Based on a comparison between the observation signal and a composite acceleration signal obtained by combining the acceleration signals based on a plurality of parameters, the device estimates a specific value of each of the parameters corresponding to acceleration components of the observation signal based on the users movement, and calculates the pulse rate of the user from a difference value obtained by subtracting a specific composite acceleration signal corresponding to the specific value of each of the estimated parameters from the observation signal.