PURPOSE: To prevent a malfunction in searching by detecting running speed of a tape from a reel rotation signal generator and surely judging kind of a marker when envelope detection and label section at the time of starting the searching exist.

CONSTITUTION: A signal recorded on a tape is read by a reproducing head 1, and is amplified by a reproducing amplifier 2, and envelope component is extracted by an envelope detection circuit 3. The period of the output signal of the reel rotation signal generator 4 is measured by a period measuring means 5 to be stored in a period holding means 6. By a first tape speed detection means 7, the output of the period measuring means 5 is compared with the output of the period holding means 6, and the running speed of the tape is obtained. By a second tape speed detection means 8, the running speed of the tape is obtained from the output of the envelope detection circuit 3. By a time constant setting means 9, any one side output of the first tape speed detection means 7 and the second tape speed detection means 8 is selected, and the time constant of the envelope detection circuit 3 is set.