PURPOSE: To provide the reserved data processor by which no trouble occurs by providing a means for receiving automatically a reservation by using a telephone from a user, and sending automatically a written reservation confirmation, a written cancel confirmation, etc., by a facsimile.

CONSTITUTION: This processor is constituted of an input/output device 1, a data processing part 2, a member master file 3, a reservation fundamental master file 4, a reservation master file 5, a cancel file 6, a cancel waiting master file 7, a voice answering part 8, a signal processing part 9, a receiving telephone equipment 10, a network 11, a user's telephone set 12, and a facsimile 13 with a telephone set, and provided with a means for transmitting an instruction from the data processing part 2 to a user in a voice, answering by depressing push-buttons of the telephone set 12 and the facsimile 13 by the user, by which a reservation procedure can be executed, and also, sending automatically a written reservation conformation by the facsimile from the data processor 2 in accordance with a request of the user.