An image processing device, comprising: a display part on which one of various types of displayable screens is displayed; a manipulation detecting part for detecting an input by a user on the screen displayed on said display part; a setting part for setting for each of the displayable screens at least one event to be detected in response to the user's input from among multiple events by associating the at least one event with the respective screen displayable on said display part; an event determining part for running, when the user's input is detected by said manipulation detecting part, from among multiple operational event determining routines (13b,13c,13d,13e,13f,13g), each of which corresponding to one of the multiple events, only the operational event determining routine corresponding to the at least one event associated by said setting part with the screen being currently displayed on said display part, thereby determining the event corresponding to the user's input; and a controlling part for controlling operations based on the event determined by said event determining part, wherein said setting part, in response to associating with one of the screens displayable on said display part a plurality of events as the at least one event to be detected in response to the user's input, sets priorities on each of the plurality of events based on the type of said screen associated with the plurality of events, and said event determining part, when said manipulation detecting part detects the user's input on said screen associated with the plurality of events, runs the operational event determining routines in descending order of said priorities of the events to which the operational event determining routines correspond. a display part on which one of various types of displayable screens is displayed; a manipulation detecting part for detecting an input by a user on the screen displayed on said display part; a setting part for setting for each of the displayable screens at least one event to be detected in response to the user's input from among multiple events by associating the at least one event with the respective screen displayable on said display part; an event determining part for running, when the user's input is detected by said manipulation detecting part, from among multiple operational event determining routines (13b,13c,13d,13e,13f,13g), each of which corresponding to one of the multiple events, only the operational event determining routine corresponding to the at least one event associated by said setting part with the screen being currently displayed on said display part, thereby determining the event corresponding to the user's input; and a controlling part for controlling operations based on the event determined by said event determining part, wherein said setting part, in response to associating with one of the screens displayable on said display part a plurality of events as the at least one event to be detected in response to the user's input, sets priorities on each of the plurality of events based on the type of said screen associated with the plurality of events, and said event determining part, when said manipulation detecting part detects the user's input on said screen associated with the plurality of events, runs the operational event determining routines in descending order of said priorities of the events to which the operational event determining routines correspond.