A ballpoint pen 10 includes: a ballpoint pen tip 20 having a writing ball 30 and a holder 21 holding the writing ball 30; a shaft tube 12 to which the rear end part of the ballpoint pen tip 20 is mounted; and ink 40 accommodated in the shaft tube 12. The holder 21 has an ink guiding hole 26 formed from the rear end thereof toward the head end thereof and a ball house 22 formed with the inner circumference near the head end of the holder 21 expanded. The writing ball 30 is formed of a zirconia sintered body with the content of an aluminum element being less than 0.1 weight %, and the ink 40 contains inorganic particles 41.