A support device configured for supporting development of a control program to be executed in a control device (100, 100-1, 100-2, 100-3) that is configured to control a control target, the support device comprising: a computing part configured to compute identification information in accordance with details of each unit program constituting the control program, wherein the computing part is configured to compute the identification information from a program code or a program object of each unit program by using a hash function; a first transferring part configured to transfer a unit program and identification information associated with the unit program to the control device; and a generating part configured to generate a changed unit program in accordance with a change operation carried out on any one unit program constituting the control program; the support device being characterized in further comprising: a second transferring part configured to transfer the changed unit program to the control device in operation on condition that a same identification information, that is an identification information associated with a unit program constituting the control program, is present in the control device, wherein the second transferring part is configured to transfer the changed unit program to the control device on a condition that all of corresponding identification information is present in the control device with respect to each of one or more unit programs on which any change operation is performed among a plurality of unit programs constituting the control program, such that, for every changed unit program that needs to be transferred to a control device, a corresponding unit program is stored in the control device and such that a match exists between identification information corresponding to the unit program in the support device and identification information corresponding to the unit program in the control device. a computing part configured to compute identification information in accordance with details of each unit program constituting the control program, wherein the computing part is configured to compute the identification information from a program code or a program object of each unit program by using a hash function; a first transferring part configured to transfer a unit program and identification information associated with the unit program to the control device; and a generating part configured to generate a changed unit program in accordance with a change operation carried out on any one unit program constituting the control program; the support device being characterized in further comprising: a second transferring part configured to transfer the changed unit program to the control device in operation on condition that a same identification information, that is an identification information associated with a unit program constituting the control program, is present in the control device, wherein the second transferring part is configured to transfer the changed unit program to the control device on a condition that all of corresponding identification information is present in the control device with respect to each of one or more unit programs on which any change operation is performed among a plurality of unit programs constituting the control program, such that, for every changed unit program that needs to be transferred to a control device, a corresponding unit program is stored in the control device and such that a match exists between identification information corresponding to the unit program in the support device and identification information corresponding to the unit program in the control device.