A touch-type input device comprising: a touch panel including a sensor array and an operation surface, wherein the sensor array includes drive electrodes and sensor electrodes overlapped with and insulated from the drive electrodes, and the drive electrodes and the sensor electrodes are arranged in a grid pattern that forms capacitors at intersections of the drive electrodes and the sensor electrodes; and a controller configured to apply a drive signal to the drive electrodes to detect touching of the operation surface of the touch panel from changes in capacitance of each capacitor, wherein the controller is configured to: determine whether or not there is a touch based on data values that each indicate an amount of change in capacitance of each capacitor from a predetermined reference value; and set the reference value by obtaining a parasitic capacitance of each capacitor when the touch-type input device is activated, characterized in that the controller is further configured to: when determining that a variation range of parasitic capacitances of the capacitors is larger than a predetermined specific range, determine that an erroneous reference value has been obtained; and re-obtain parasitic capacitances of the capacitors when determining that the erroneous reference value has been obtained. a touch panel including a sensor array and an operation surface, wherein the sensor array includes drive electrodes and sensor electrodes overlapped with and insulated from the drive electrodes, and the drive electrodes and the sensor electrodes are arranged in a grid pattern that forms capacitors at intersections of the drive electrodes and the sensor electrodes; and a controller configured to apply a drive signal to the drive electrodes to detect touching of the operation surface of the touch panel from changes in capacitance of each capacitor, wherein the controller is configured to: determine whether or not there is a touch based on data values that each indicate an amount of change in capacitance of each capacitor from a predetermined reference value; and set the reference value by obtaining a parasitic capacitance of each capacitor when the touch-type input device is activated, determine whether or not there is a touch based on data values that each indicate an amount of change in capacitance of each capacitor from a predetermined reference value; and set the reference value by obtaining a parasitic capacitance of each capacitor when the touch-type input device is activated, characterized in that the controller is further configured to: when determining that a variation range of parasitic capacitances of the capacitors is larger than a predetermined specific range, determine that an erroneous reference value has been obtained; and re-obtain parasitic capacitances of the capacitors when determining that the erroneous reference value has been obtained. when determining that a variation range of parasitic capacitances of the capacitors is larger than a predetermined specific range, determine that an erroneous reference value has been obtained; and re-obtain parasitic capacitances of the capacitors when determining that the erroneous reference value has been obtained.