A method for remote assistance using a remote assistant system configured to be applied to a foundry, the remote assistant system being characterized in that the system comprises at least a touchscreen panel for operating a molding line having a molding machine, a first sequencer for controlling the molding line, a touchscreen panel for operating the molding machine, and a second sequencer for controlling the molding machine, the system further comprising: a sequencer-communicating means for connecting the first sequencer to the second sequencer; a first mobile computer adapted to take information by video images and information by voice on an appearance of the molding machine or the molding line that has trouble and information on a ladder logic program of the first sequencer or the second sequencer of the molding line or the molding machine that has trouble, and adapted to transmit the information by video images, the information by voice, or the information on the ladder logic program of the first or second sequencer (4, 6); a wireless communication means for selectively connecting one of the sequencers (4, 6) to the first mobile computer; and a second mobile computer adapted to receive the information by video images, the information by voice, or the information on the ladder logic program of the first or second sequencer (4, 6) from the first mobile computer, and displaying the information, the second mobile computer is adapted to transmit online data for correcting the ladder logic program and instructions for repairing the molding machine or the molding line, the method comprising the steps of: searching for a first possible location that has trouble by moving the first mobile computer to obtain information by video images or by voice regarding the molding line or the molding machine, the first possible location being derived from an appearance; identifying a second possible location in the molding machine or the molding line that has trouble by using information on the ladder logic program that is displayed on the second mobile computer; determining a location that has trouble by checking to see if the first possible location is the same as the second possible location; and giving instructions to repair the molding machine or molding line based on the result of the step of determining. a sequencer-communicating means for connecting the first sequencer to the second sequencer; a first mobile computer adapted to take information by video images and information by voice on an appearance of the molding machine or the molding line that has trouble and information on a ladder logic program of the first sequencer or the second sequencer of the molding line or the molding machine that has trouble, and adapted to transmit the information by video images, the information by voice, or the information on the ladder logic program of the first or second sequencer (4, 6); a wireless communication means for selectively connecting one of the sequencers (4, 6) to the first mobile computer; and a second mobile computer adapted to receive the information by video images, the information by voice, or the information on the ladder logic program of the first or second sequencer (4, 6) from the first mobile computer, and displaying the information, the second mobile computer is adapted to transmit online data for correcting the ladder logic program and instructions for repairing the molding machine or the molding line, the method comprising the steps of: searching for a first possible location that has trouble by moving the first mobile computer to obtain information by video images or by voice regarding the molding line or the molding machine, the first possible location being derived from an appearance; identifying a second possible location in the molding machine or the molding line that has trouble by using information on the ladder logic program that is displayed on the second mobile computer; determining a location that has trouble by checking to see if the first possible location is the same as the second possible location; and giving instructions to repair the molding machine or molding line based on the result of the step of determining. searching for a first possible location that has trouble by moving the first mobile computer to obtain information by video images or by voice regarding the molding line or the molding machine, the first possible location being derived from an appearance; identifying a second possible location in the molding machine or the molding line that has trouble by using information on the ladder logic program that is displayed on the second mobile computer; determining a location that has trouble by checking to see if the first possible location is the same as the second possible location; and giving instructions to repair the molding machine or molding line based on the result of the step of determining.