[Task] It is to propose a method of producing Ta powder for a tantalum solid electrolytic capacitor capable of stably providing a CV value of more than 220 k and to provide the Ta powder and its Ta granulated powder. [Solution] In a method of producing a Ta powder by vaporizing TaCl 5 through heating and reducing with H 2 gas, the reduction is performed under conditions that a feeding rate of TaCl 5 vapor passing through a section area of a reaction field of 1 cm 2 for 1 minute is 0.05ˆ¼5.0 g/ cm 2 · min and a residence time of TaCl 5 vapor in the reduction reaction field is 0.1ˆ¼5 seconds and a reduction temperature of TaCl 5 is 1100ˆ¼1600C, whereby Ta powder comprised of a single phase of ²-Ta of tetragonal system or a mixed phase of ²-Ta and ±-Ta of cubic system and having an average particle size of 30ˆ¼150 nm is obtained. Further, a Ta granulated powder is obtained by granulating the Ta powder.
