An information display device comprising: a display section; a touchscreen panel, which forms an integral part of the display section and which has an input area that is associated with the display area of the display section; an area locating section for determining, in response to a user's action on the input area, what partial area of the input area has been operated on as a result of the user's action, thereby generating a signal specifying that partial area; a counting section adapted to count, on a partial area basis, the frequency of the user's actions in a non-cleaning mode that is different from a cleaning mode; and a control section adapted to instruct the display section to display a semitransparent pattern, such that - when the cleaning mode is entered, the degree of transparency of the semi-transparent pattern to be displayed initially on the display area changes on a partial area basis according to the frequency that has been counted in the non-cleaning mode that is stored in a frequency of contact storage section for each said partial area; and - when in the cleaning mode for cleaning the input area, the display section superimposes the semi-transparent pattern on an image that is presented on the display area thereof so that the image can still be seen to the user through the semi-transparent pattern, and increases the degree of transparency of that pattern on the partial area according to the frequency of contact in the cleaning mode. a display section; a touchscreen panel, which forms an integral part of the display section and which has an input area that is associated with the display area of the display section; an area locating section for determining, in response to a user's action on the input area, what partial area of the input area has been operated on as a result of the user's action, thereby generating a signal specifying that partial area; a counting section adapted to count, on a partial area basis, the frequency of the user's actions in a non-cleaning mode that is different from a cleaning mode; and a control section adapted to instruct the display section to display a semitransparent pattern, such that - when the cleaning mode is entered, the degree of transparency of the semi-transparent pattern to be displayed initially on the display area changes on a partial area basis according to the frequency that has been counted in the non-cleaning mode that is stored in a frequency of contact storage section for each said partial area; and - when in the cleaning mode for cleaning the input area, the display section superimposes the semi-transparent pattern on an image that is presented on the display area thereof so that the image can still be seen to the user through the semi-transparent pattern, and increases the degree of transparency of that pattern on the partial area according to the frequency of contact in the cleaning mode. - when the cleaning mode is entered, the degree of transparency of the semi-transparent pattern to be displayed initially on the display area changes on a partial area basis according to the frequency that has been counted in the non-cleaning mode that is stored in a frequency of contact storage section for each said partial area; and - when in the cleaning mode for cleaning the input area, the display section superimposes the semi-transparent pattern on an image that is presented on the display area thereof so that the image can still be seen to the user through the semi-transparent pattern, and increases the degree of transparency of that pattern on the partial area according to the frequency of contact in the cleaning mode.