A biological information detector includes a wristband, a light-emitting part, a reflecting part, a light-receiving part, a protecting part, an acceleration sensor and a processing part. The wristband is adapted to be attached to a body of a user. The light-emitting part is configured to emit green light. The reflecting part is configured to reflect the light emitted by the light-emitting part. The light-receiving part is configured to receive reflected light reflected at a detection site of the body of the user. The protecting part is configured to protect the light-emitting part, the protecting part having a contact surface configured to contact with the detection site. The acceleration sensor is configured to detect acceleration generated by the user. The processing part is configured to process a light reception signal outputted from the light-receiving part.