A remote operation system for remotely operating a construction machine including an operation member, the remote operation system comprising: a master operation device configured to remotely operate the construction machine; and a slave operation device mountable to the construction machine and configured to operate the construction machine based on an operation received by the master operation device, wherein the master operation device includes: a remote operation member configured to receive an operation of an operator; a first sensor configured to detect an operation amount of the remote operation member; a first communication unit configured to transmit the operation amount detected by the first sensor to the slave operation device; and a warning device configured to issue an alarm, the slave operation device includes: a second communication unit configured to receive the operation amount transmitted from the master operation device; an operation mechanism configured to directly operate the operation member of the construction machine; a second sensor configured to detect an operation amount of the operation member of the construction machine; and a slave side controller configured to control the operation mechanism to operate the operation member of the construction machine with the operation amount received by the second communication unit, characterised in that on detection of a difference between the operation amount detected by the second sensor and the operation amount received by the second communication unit, the slave side controller executes stop control to automatically stop the construction machine, the control to automatically stop the construction machine being control to gradually decrease an engine speed of the construction machine to an idle state and then stop the engine. a master operation device configured to remotely operate the construction machine; and a slave operation device mountable to the construction machine and configured to operate the construction machine based on an operation received by the master operation device, wherein the master operation device includes: a remote operation member configured to receive an operation of an operator; a first sensor configured to detect an operation amount of the remote operation member; a first communication unit configured to transmit the operation amount detected by the first sensor to the slave operation device; and a warning device configured to issue an alarm, a remote operation member configured to receive an operation of an operator; a first sensor configured to detect an operation amount of the remote operation member; a first communication unit configured to transmit the operation amount detected by the first sensor to the slave operation device; and a warning device configured to issue an alarm, the slave operation device includes: a second communication unit configured to receive the operation amount transmitted from the master operation device; an operation mechanism configured to directly operate the operation member of the construction machine; a second sensor configured to detect an operation amount of the operation member of the construction machine; and a slave side controller configured to control the operation mechanism to operate the operation member of the construction machine with the operation amount received by the second communication unit, characterised in that a second communication unit configured to receive the operation amount transmitted from the master operation device; an operation mechanism configured to directly operate the operation member of the construction machine; a second sensor configured to detect an operation amount of the operation member of the construction machine; and a slave side controller configured to control the operation mechanism to operate the operation member of the construction machine with the operation amount received by the second communication unit, characterised in that on detection of a difference between the operation amount detected by the second sensor and the operation amount received by the second communication unit, the slave side controller executes stop control to automatically stop the construction machine, the control to automatically stop the construction machine being control to gradually decrease an engine speed of the construction machine to an idle state and then stop the engine.