A blade main body (51) of a gas turbine is provided with a first cooling passage part (58), a second cooling passage part (59), a column part (60), and a plurality of protrusions. The first cooling passage part (58) is provided at the side near to a leading edge (55). The second cooling passage part (59) is provided at the side near to a trailing edge (56). The column part (60) is provided between the first cooling passage part (58) and the second cooling passage part (59), and is continuously formed between a base part and an end part of the blade main body (51). The protrusions protrude from the inner wall surfaces of the first cooling passage part (58) and the second cooling passage part (59).