In this paper, we explain a typical deep learning system called “Deep Convolution Neural Network : DCNN”,which becomes to be de facto standard in the field of computer vision. Moreover, we also explain an application a DCNN into the medical image analysis for the computer aided diagnosis. Considering the balance between sample size and the number of weight is a important factor for developing a deep learning system, however, acquiring the data is hard task in the field of medical imaging. Thus, we introduce a kind of transfer learning method into the DCNN. As the result, we confirm the improvement of classification performance for the diffuse lung disease(DLD)patterns.