To provide a financial accounting processing apparatus and a financial accounting processing method, which can easily journalize charged and non- charged contents.

This apparatus is provided with a composite journalizing master storage means for storing a plurality of outline data including a plurality of account items divided into taxable and tax-free items and having codes, a 1st display means allowed to be accessed about the outline data from the master storage means and capable of displaying a plurality of accounting items belonging to the outline corresponding to the code and a tax included amount column, a tax amount column and a tax excluded amount column corresponding to the accounting item, an arithmetic means for automatically calculating a tax amount and a tax excluded amount while referring to a tax division by inputting the tax included amount to the tax included amount column displayed on the 1st display means, a 2nd display means for respectively displaying the calculated tax amount and the tax excluded amount in the tax amount column and the tax excluded amount column, and a storage means for storing the tax included amount, the tax amount and the tax excluded amount.