A controller support apparatus comprising a storage unit (82, 83, 84) and an operation unit, wherein said storage unit (82, 83, 84) is used for storing: a controller support program; and calibration data representing a relation between a first test execution time and a second test execution time, said first test execution time is an execution time of a first test program which is an object program generated from a test source program and operating at a simulator of a programmable logic controller, and said first test execution time is measured at said simulator, said second test execution time is an execution time of a second test program which is an object program generated from said test source program and operating at said programmable logic controller, and said second test execution time is measured at said programmable logic controller, and said controller support program causes said operation unit to execute: a process of acquiring a first control execution time which is an execution time of a first control program which is an object program generated from a control source program, which is a source program of a control program generated in accordance with an object of control of a user, and operating at said simulator, and said first control execution time is measured at said simulator; a process of calculating an estimated execution time which is an estimated value of an execution time, at said programmable logic controller, of a second control program which is an object program generated from said control source program and operating at said programmable logic controller, by converting said first control execution time using said calibration data; and a process_ for outputting data representing said estimated execution time. a controller support program; and calibration data representing a relation between a first test execution time and a second test execution time, said first test execution time is an execution time of a first test program which is an object program generated from a test source program and operating at a simulator of a programmable logic controller, and said first test execution time is measured at said simulator, said second test execution time is an execution time of a second test program which is an object program generated from said test source program and operating at said programmable logic controller, and said second test execution time is measured at said programmable logic controller, and said controller support program causes said operation unit to execute: a process of acquiring a first control execution time which is an execution time of a first control program which is an object program generated from a control source program, which is a source program of a control program generated in accordance with an object of control of a user, and operating at said simulator, and said first control execution time is measured at said simulator; a process of calculating an estimated execution time which is an estimated value of an execution time, at said programmable logic controller, of a second control program which is an object program generated from said control source program and operating at said programmable logic controller, by converting said first control execution time using said calibration data; and a process_ for outputting data representing said estimated execution time. a process of acquiring a first control execution time which is an execution time of a first control program which is an object program generated from a control source program, which is a source program of a control program generated in accordance with an object of control of a user, and operating at said simulator, and said first control execution time is measured at said simulator; a process of calculating an estimated execution time which is an estimated value of an execution time, at said programmable logic controller, of a second control program which is an object program generated from said control source program and operating at said programmable logic controller, by converting said first control execution time using said calibration data; and a process_ for outputting data representing said estimated execution time.