An in-vehicle processing device mounted on a vehicle, comprising: a signal input unit configured to generate input data based on an external input signal, a processing unit configured to execute arithmetic processing for calculating output data based on the input data, a signal output unit configured to generate an output signal based on the output data to externally output the output signal, and a storage unit configured to store application software for causing the processing unit to execute the arithmetic processing, wherein the application software includes: a data management layer for managing object data, which is a group of individual information elements corresponding to a given target element which corresponds to detection targets of various sensors, on the storage unit, a data adaptation layer for generating the object data based on the input data to output the generated object data to the data management layer, and a data operation layer for acquiring the object data from the data management layer to calculate the output data based on the acquired object data, wherein the data management layer has an interface for the data adaptation layer and the data operation layer to process the object data managed by the data management layer, and the interface is configured to be able to process a plurality of the object data pieces having different data structures by a common operation method. a signal input unit configured to generate input data based on an external input signal, a processing unit configured to execute arithmetic processing for calculating output data based on the input data, a signal output unit configured to generate an output signal based on the output data to externally output the output signal, and a storage unit configured to store application software for causing the processing unit to execute the arithmetic processing, wherein the application software includes: a data management layer for managing object data, which is a group of individual information elements corresponding to a given target element which corresponds to detection targets of various sensors, on the storage unit, a data adaptation layer for generating the object data based on the input data to output the generated object data to the data management layer, and a data operation layer for acquiring the object data from the data management layer to calculate the output data based on the acquired object data, wherein the data management layer has an interface for the data adaptation layer and the data operation layer to process the object data managed by the data management layer, and the interface is configured to be able to process a plurality of the object data pieces having different data structures by a common operation method. a data management layer for managing object data, which is a group of individual information elements corresponding to a given target element which corresponds to detection targets of various sensors, on the storage unit, a data adaptation layer for generating the object data based on the input data to output the generated object data to the data management layer, and a data operation layer for acquiring the object data from the data management layer to calculate the output data based on the acquired object data, wherein the data management layer has an interface for the data adaptation layer and the data operation layer to process the object data managed by the data management layer, and the interface is configured to be able to process a plurality of the object data pieces having different data structures by a common operation method.