The present invention discloses a coated cutting tool having a hard coating film on a surface of the tool. The hard coating film is a nitride, the content ratio of titanium (Ti) with respect to a total amount of metal elements (including semimetal elements) is in a range of 70 at % to 95 at %, the content ratio of silicon (Si) with respect to the total amount of metal elements (including semimetal elements) is in a range of 5 at % to 30 at %, and the content ratio of argon (Ar) with respect to the total amount of metal elements (including semimetal elements) and non-metal elements is 0.1 at % or less. The hard coating film has a NaCl type crystal structure and has an average crystal grain size in a range of 5 nm to 30 nm.