4 In cases where a corporation, which is a researcher, obtained the approval under the provision of paragraph 1, if it has acquired or constracted the approved machines, equipments, etc. and put them into use for the approved research, within one year after the date of the approval, the limit amount of depreciation expenses for such machines, equipments, etc. to be computed in accordance with the provisions of the Corporation Tax Law (Law No.28 of 1947) or Order issued thereunder, which allow to count it in business expenses in computation of its business income under the same Law, as for each accounting period covering the days within three years after the day on which such machines, equipments, etc. were put into use for the research, shall, notwithstanding the said provisions, be calculated by multiplying the amount equivalent to 90% of the cost for acquisition or construction of such machines, equipments, etc. by the number of months during the period concerned out of the accounting period concerned and then divided by 36, only within three years after the day on which such machines, equipments, etc. were put into use for the research and when they are putting into such use.