A development support device that supports a user to write a program executed by a controller, the development support device, characterized by, comprising: an operation receiving unit that receives a user operation indicating an instruction to output comments on target variables used in the program, the comments being able to be attached to definitions of the variables by a user; and an output unit that acquires a name of a first variable corresponding to ancestor node of the target variables, acquires discrimination information of discriminating the target variables from a plurality of second variables corresponding to other descendant nodes of which an ancestor node is the first variable, acquires the comments on the target variables, generates one character string combined with the name of the first variable and the discrimination information, and outputs a list formed by associating the comments on the target variables with the character string as a file with a data format which is editable in at least one of a text editor and spreadsheet software, wherein the first variable is an array type variable or a structure type variable, wherein each of the plurality of second variables is an element of the array type variable or a member of the structure type variable, wherein the discrimination information includes path information indicating a path from the first variable to each of the plurality of second variables in the tree data structure, and wherein the path information provides each of one or more parent-child relationships from the first variable to each of the plurality of second variables in the tree data structure by using brackets, when a variable corresponding to a parent node is an array type variable and a variable corresponding to a child node is an element of the array type variable, and a period, when a variable corresponding to a parent node is a structure type variable and a variable corresponding to a child node is a member of the structure type variable. an operation receiving unit that receives a user operation indicating an instruction to output comments on target variables used in the program, the comments being able to be attached to definitions of the variables by a user; and an output unit that acquires a name of a first variable corresponding to ancestor node of the target variables, acquires discrimination information of discriminating the target variables from a plurality of second variables corresponding to other descendant nodes of which an ancestor node is the first variable, acquires the comments on the target variables, generates one character string combined with the name of the first variable and the discrimination information, and outputs a list formed by associating the comments on the target variables with the character string as a file with a data format which is editable in at least one of a text editor and spreadsheet software, wherein the first variable is an array type variable or a structure type variable, wherein each of the plurality of second variables is an element of the array type variable or a member of the structure type variable, wherein the discrimination information includes path information indicating a path from the first variable to each of the plurality of second variables in the tree data structure, and wherein the path information provides each of one or more parent-child relationships from the first variable to each of the plurality of second variables in the tree data structure by using brackets, when a variable corresponding to a parent node is an array type variable and a variable corresponding to a child node is an element of the array type variable, and a period, when a variable corresponding to a parent node is a structure type variable and a variable corresponding to a child node is a member of the structure type variable.