A biometric information detecting device includes a measurer, a determiner, a controller, and a processor. The measurer measures biometric information of a user as an electrical signal. The determiner is connected to the measurer to receive the electrical signal, processes the electrical signal according to a first reference condition to output a first result signal, and processes the electrical signal according to a second reference condition to output a second result signal. The controller controls the determiner such that the determiner is operated in the first reference condition or the second reference condition, and the processor processes the first and second result signals to obtain the biometric information of the user.