A Ni-based corrosion resistant alloy powder for additive manufacturing, composed of a powder of a Ni-based alloy having a component composition including, in mass%, Cr: 14.5 to 24.5%, Mo: 12.0 to 23.0%, Fe: 0.01 to 7.00%, Co: 0.001 to 2.500%, Mg: 0.010% or less, N: 0.040% or less, Mn: 0.001 to 0.50%, Si: 0.001 to 0.200%, Al: more than 0 and 0.50% or less, Ti: 0.001 to 0.500%, Cu: 0.250% or less, V: 0.001 to 0.300%, B: 0.0001 to 0.0050%, Zr: 0.0001 to 0.0200%, O: 0.0010 to 0.0300%, and optionally, Ta: 2.5% or less or W: 5.0% or less, with the remainder being Ni and unavoidable impurities, wherein C, S and P are contained as the unavoidable impurities (C: less than 0.05%, S: less than 0.01% and P: less than 0.01%), and wherein a repose angle of the Ni-based alloy powder is 48 degrees or less, and the repose angle was measured according to JIS R9301-2-2 by using a repose angle measurement instrument ASK-01, in the Ni-based alloy powder, in a cumulative distribution curve showing the relationship between a particle size and a cumulative volume from a small particle size side obtained by a laser diffraction method, a particle size d10 corresponding to a cumulative frequency of 10 volume% of the powder is 7 μm or more and 35 μm or less, a particle size d50 corresponding to a cumulative frequency of 50 volume% of the powder is 10 μm or more and 60 μm or less, a particle size d90 corresponding to a cumulative frequency of 90 volume% of the powder is 20 μm or more and 98 μm or less, and in the cumulative distribution curve, the uniformity represented by (d90-d10)/d50 is 1.5 or less. in mass%, Cr: 14.5 to 24.5%, Mo: 12.0 to 23.0%, Fe: 0.01 to 7.00%, Co: 0.001 to 2.500%, Mg: 0.010% or less, N: 0.040% or less, Mn: 0.001 to 0.50%, Si: 0.001 to 0.200%, Al: more than 0 and 0.50% or less, Ti: 0.001 to 0.500%, Cu: 0.250% or less, V: 0.001 to 0.300%, B: 0.0001 to 0.0050%, Zr: 0.0001 to 0.0200%, O: 0.0010 to 0.0300%, and optionally, Ta: 2.5% or less or W: 5.0% or less, with the remainder being Ni and unavoidable impurities, wherein C, S and P are contained as the unavoidable impurities (C: less than 0.05%, S: less than 0.01% and P: less than 0.01%), and wherein a repose angle of the Ni-based alloy powder is 48 degrees or less, and the repose angle was measured according to JIS R9301-2-2 by using a repose angle measurement instrument ASK-01, in the Ni-based alloy powder, in a cumulative distribution curve showing the relationship between a particle size and a cumulative volume from a small particle size side obtained by a laser diffraction method, a particle size d10 corresponding to a cumulative frequency of 10 volume% of the powder is 7 μm or more and 35 μm or less, a particle size d50 corresponding to a cumulative frequency of 50 volume% of the powder is 10 μm or more and 60 μm or less, a particle size d90 corresponding to a cumulative frequency of 90 volume% of the powder is 20 μm or more and 98 μm or less, and in the cumulative distribution curve, the uniformity represented by (d90-d10)/d50 is 1.5 or less. wherein C, S and P are contained as the unavoidable impurities (C: less than 0.05%, S: less than 0.01% and P: less than 0.01%), and wherein a repose angle of the Ni-based alloy powder is 48 degrees or less, and the repose angle was measured according to JIS R9301-2-2 by using a repose angle measurement instrument ASK-01, in the Ni-based alloy powder, in a cumulative distribution curve showing the relationship between a particle size and a cumulative volume from a small particle size side obtained by a laser diffraction method, a particle size d10 corresponding to a cumulative frequency of 10 volume% of the powder is 7 μm or more and 35 μm or less, a particle size d50 corresponding to a cumulative frequency of 50 volume% of the powder is 10 μm or more and 60 μm or less, a particle size d90 corresponding to a cumulative frequency of 90 volume% of the powder is 20 μm or more and 98 μm or less, and in the cumulative distribution curve, the uniformity represented by (d90-d10)/d50 is 1.5 or less.