PURPOSE: To obtain a fire prevention device possible to prevent certainly the occurrence of a fire, etc., of a copying machine whatever faults occur in a connection device, for example the body side of the copying machine.

CONSTITUTION: A structure 200 independent quite separately to the body of a copying machine 100 is provided, and several kinds of sensors 20 to 27 are arranged in parts possible to cause a fire in the copying machine 100. A CPU 201 stores several data of state parameters of several parts to a RAM 203 as time series data; operates as a neural network consisting of an input layer being an aggregate of input units to input each of several stored time series data, a middle layer being an aggregate of a plurality of middle layer units combined to at least one part of several input units of the input layer, and an output layer being an aggregate of output units combined to at least one part of a plurality of middle units and set up corresponding to a plurality of movable conditions; recognizes the conditions within the copying machine as one of the conditions previously classified; and carries out a fire prevention measure to accord with the recognized conditions.