Office paper and production method of office paper

The invention relates to an office paper and a production method of the office paper. The office paper comprises a paper base, and is subjected to surface sizing. The paper base comprises inorganic filler; the inorganic filler comprises inorganic material; the particle size of 95% of inorganic filler is less than 5 micrometers; the particle size distribution span delta D which is equal to (D90-D10)/D50 (I) is less than 2.2, and is preferentially less than 1.5 and particularly less than 0.8; preferentially, the inorganic material particles are calcium carbonate particles which are obtained by dry and wet grinding.