To retrieve the specification and arrangement of a cooling element in a short time by executing a thermal analysis of forced air cooling based upon the arrangement of the cooling element, and outputting the result of the thermal analysis.

A cooling element selection processing part 3 executes a thermal analysis of a closed natural air cooling based upon an analysis model prepared in a natural air cooling preprocessing part 1, and extracts and calculates a specified temperature region outside region based upon the analysis result to select various conditions of the cooling element. The thermal analysis is executed in a forced air cooling analysis processing part 5. At this time, an analysis model for the calculation is prepared in a mesh creation processing part 5a, and based upon the analysis model an analysis with numerical operation is executed in a thermal analysis processing part 5b. The analysis result is outputted from a result output processing part 7. At this time, since a premise of the various conditions of the cooling element is estimated in the cooling element selection processing part 3 so that for the processing in the forced air cooling analysis processing part 5 accuracy of the thermal analysis is improved and hence the number of times of recalculation with trial and error is sharply reduced.