PURPOSE: To perform an automatic estimating calculation at a remote place for a building, etc., by discriminating a voice signal via a telephone circuit to control a computer.

CONSTITUTION: A prescribed telephone called out via a telephone circuit gives an answer through its automatic answering device 9. The voice of a remote operator is converted into a prescribed electric signal by a voice listening device 2 via a handset 1 and then fed into a computer 5 via an action instruction analyzer 4. The computer 5 prepares a desired estimation calculating program (a) and data bank (b) and performs an estimating calculation on the basis of the product number, size, etc. obtained from the voice information given from telephone circuit. Then the computer 5 prints out the result of calculation through a printer 6, transmits the result of estimation and the desired data to the telephone circuit via a voice generating device 3 and an output program and gives this information to a remote caller in voice. It is also possible to feed the necessary data into the computer 5 via an optical reader 7 and a tape input device 8 and with no intervention of a telephone circuit.