An information reproducing apparatus detects a reproducing area on a disk having information recorded thereon at an approximately constant linear velocity. A reproduced signal is generated by rotating the disk mounted on a shaft of a motor, and reading out the information recorded on the rotating disk with an information reproducing head. A frequency detecting circuit generates a frequency signal indicative of the number of rotations of the motor. This frequency signal is compared with the reproduced signal to detect the number of pulses of the reproduced signal contained in one period of the frequency signal. A reproducing area on the disk is detected by comparing the detected number of pulses with a predetermined value, since this number of pulses has a value corresponding to a radial position on the disk.