WRITING INSTRUMENT

摘要

PROBLEM TO BE SOLVED: To provide a writing instrument which enables an ink tank to be decompressed when a cap is opened thereby preventing an ink from leaking from a pen point during use even if a pressure in the ink tank for housing the ink increases when the writing instrument is stored and is suitable for a ball point pen and a marking pen.SOLUTION: A writing instrument A includes an ink tank 11 filled with an ink 25 in a writing instrument body 10. A pen point 20 and a cap body 30 which seals the pen point 20 are attached to a front part of the writing instrument body 10. The cap body 30 includes a decompression mechanism 40 which decompresses the ink tank 11 as the cap body is opened.