A program development support device, configured to be couplable to a sequence control simulator configured to execute a simulation of a sequence control program and to an HMI control simulator configured to execute a simulation of a HMI control program through a communication network, and the program development support device comprising: a sequence control editing unit configured to edit the sequence control program; an HMI control editing unit configured to edit the HMI control program; and an integration simulation management unit comprising: a variable management unit configured to exchange common variables of the sequence control program and the HMI control program between the sequence control simulator that is configured to execute the simulation of the sequence control program and the HMI control simulator that is configured to execute the simulation of the HMI control program when the simulation of the sequence control program and the simulation of the HMI control program are executed, characterized in that the integration simulation management unit is configured to manage synchronization of runtime of the simulation of the sequence control program and runtime of the simulation of the HMI control program, wherein managing of synchronization is executed while checking exchanging of common variables of mutual programs, and if a breakpoint set to one of the sequence control program and the HMI control program is detected, the program development support device is configured to pause execution of the simulation of the sequence control program by the sequence control simulator and execution of the simulation of the HMI control program by the HMI control simulator so as to perform debug of the HMI control program and debug of the HMI control program. a sequence control editing unit configured to edit the sequence control program; an HMI control editing unit configured to edit the HMI control program; and an integration simulation management unit comprising: a variable management unit configured to exchange common variables of the sequence control program and the HMI control program between the sequence control simulator that is configured to execute the simulation of the sequence control program and the HMI control simulator that is configured to execute the simulation of the HMI control program when the simulation of the sequence control program and the simulation of the HMI control program are executed, characterized in that the integration simulation management unit is configured to manage synchronization of runtime of the simulation of the sequence control program and runtime of the simulation of the HMI control program, wherein managing of synchronization is executed while checking exchanging of common variables of mutual programs, and if a breakpoint set to one of the sequence control program and the HMI control program is detected, the program development support device is configured to pause execution of the simulation of the sequence control program by the sequence control simulator and execution of the simulation of the HMI control program by the HMI control simulator so as to perform debug of the HMI control program and debug of the HMI control program. a variable management unit configured to exchange common variables of the sequence control program and the HMI control program between the sequence control simulator that is configured to execute the simulation of the sequence control program and the HMI control simulator that is configured to execute the simulation of the HMI control program when the simulation of the sequence control program and the simulation of the HMI control program are executed, characterized in that the integration simulation management unit is configured to manage synchronization of runtime of the simulation of the sequence control program and runtime of the simulation of the HMI control program, wherein managing of synchronization is executed while checking exchanging of common variables of mutual programs, and if a breakpoint set to one of the sequence control program and the HMI control program is detected, the program development support device is configured to pause execution of the simulation of the sequence control program by the sequence control simulator and execution of the simulation of the HMI control program by the HMI control simulator so as to perform debug of the HMI control program and debug of the HMI control program.