Abstract: A processing apparatus 1 includes a determiner 30 that compares state information, which is information pertaining to states obtained from a field, and performs processing related to a determiner 30 based on information specifying a content of a comparison in the determiner and an operation pertaining to a state transition according to the result of the comparison, and on information pertaining to generation of a state information generator for generating the state information from the information pertaining to the state of the field. The information specifying the contents of the comparison in the determiner 30 and the operation pertaining to the state transition according to the result of the comparison, and the information pertaining to the generation of the state information generator for generating the state information from the information pertaining to the state of the field can be changed regardless of the operation of the determiner 30.