A development support device for developing a plurality of different programming languages that are executed in a control device, characterized in that the development support device comprises: an input unit (51, 71) configured to input source code of one programming language and source code of another programming language, and input a shared variable reference (TBL1, TBL2) comprising a plurality of variables from the source code of the one programming language and the source code of the other programming language, wherein the shared variable reference is pre-created at the time a shared variable from one of the source code of the one programming language and the source code of the other programming language is defined; a determination unit (53, 73d, 73f) configured to perform a check variable process to determine whether the shared variable inputted matches a variable from the source code of the one programming language and a variable from the source code of the other programming language according to the plurality of variables in the shared variable reference (TBL1, TBL2); and a display unit (52, 72) configured to output a message based on the check variable process, wherein the display unit (52, 72) is configured to output a message indicating that a compilation is successful when the shared variable matches the variable from the source code of the one programming language and the shared variable matches the variable from the source code of the other programming language, and output a message indicating that the compilation has failed when the share variable does not match the variable from the source code of the one programming language or the variable from the source code of the other programming language. an input unit (51, 71) configured to input source code of one programming language and source code of another programming language, and input a shared variable reference (TBL1, TBL2) comprising a plurality of variables from the source code of the one programming language and the source code of the other programming language, wherein the shared variable reference is pre-created at the time a shared variable from one of the source code of the one programming language and the source code of the other programming language is defined; a determination unit (53, 73d, 73f) configured to perform a check variable process to determine whether the shared variable inputted matches a variable from the source code of the one programming language and a variable from the source code of the other programming language according to the plurality of variables in the shared variable reference (TBL1, TBL2); and a display unit (52, 72) configured to output a message based on the check variable process, wherein the display unit (52, 72) is configured to output a message indicating that a compilation is successful when the shared variable matches the variable from the source code of the one programming language and the shared variable matches the variable from the source code of the other programming language, and output a message indicating that the compilation has failed when the share variable does not match the variable from the source code of the one programming language or the variable from the source code of the other programming language.