A graph display device comprising: an expression input unit that recognizes input of a functional expression; a graph display control unit that displays a graph corresponding to the functional expression recognized by the expression input unit in a display part; a first display control unit that displays a first slider (Sa, Sb, Sc) for changing a numeric value set to a variable, the first slider (Sa, Sb, Sc) being displayed together with the graph in the display part when a coefficient (A, B, C) included in the functional expression is the variable; a second display control unit that displays a second slider (Sa, Sb, Sc) for changing a numeric value of a constant, the second slider (Sa, Sb, Sc) being displayed together with the graph in the display part in accordance with a user operation after the graph is displayed in the display part when a coefficient (A, B, C) included in the functional expression is the constant; a coefficient changed graph display control unit that displays, in the display part, a graph (Y') corresponding to the functional expression in which a numeric value changed by a user operation of the first slider (Sa, Sb, Sc) or the second slider (Sa, Sb, Sc) is set as a value of the coefficient (A, B, C); and a numeric value variable range change unit that changes a range of numeric values designated by the first slider (Sa, Sb, Sc) or the second slider (Sa, Sb, Sc), wherein, when a cursor (Cs) of the respective slider (Sa, Sb, Sc) is held in an end part of the respective slider (Sa, Sb, Sc) for a prescribed time or more, the range of numeric values designated by the respective slider (Sa, Sb, Sc) is changed to a new range of numeric values in which a value of the end part is set as a median. an expression input unit that recognizes input of a functional expression; a graph display control unit that displays a graph corresponding to the functional expression recognized by the expression input unit in a display part; a first display control unit that displays a first slider (Sa, Sb, Sc) for changing a numeric value set to a variable, the first slider (Sa, Sb, Sc) being displayed together with the graph in the display part when a coefficient (A, B, C) included in the functional expression is the variable; a second display control unit that displays a second slider (Sa, Sb, Sc) for changing a numeric value of a constant, the second slider (Sa, Sb, Sc) being displayed together with the graph in the display part in accordance with a user operation after the graph is displayed in the display part when a coefficient (A, B, C) included in the functional expression is the constant; a coefficient changed graph display control unit that displays, in the display part, a graph (Y') corresponding to the functional expression in which a numeric value changed by a user operation of the first slider (Sa, Sb, Sc) or the second slider (Sa, Sb, Sc) is set as a value of the coefficient (A, B, C); and a numeric value variable range change unit that changes a range of numeric values designated by the first slider (Sa, Sb, Sc) or the second slider (Sa, Sb, Sc), wherein, when a cursor (Cs) of the respective slider (Sa, Sb, Sc) is held in an end part of the respective slider (Sa, Sb, Sc) for a prescribed time or more, the range of numeric values designated by the respective slider (Sa, Sb, Sc) is changed to a new range of numeric values in which a value of the end part is set as a median.