A method for producing a catalyst to be used for a gas-phase catalytic ammoxidation reaction of propane, the method comprising: a preparation step of dissolving or dispersing a raw material to thereby obtain a prepared raw material liquid; a first drying step of drying the prepared raw material liquid to thereby obtain a dried material; a calcination step of calcining the dried material to thereby obtain a composite oxide represented by following formula: Mo 1 V a Nb b A c X d Z e O n... wherein A represents at least one element selected from the group consisting of Sb and Te; X represents at least one element selected from the group consisting of W, Bi, Mn and Ti; and Z represents at least one element selected from the group consisting of La, Ce, Pr, Yb, Y, Sc, Sr and Ba; and a, b, c, d, e and n represent elemental ratios of the respective elements per one element of Mo and 0.01 ≤ a ≤ 1.00, 0.01 ≤ b ≤ 1.00, 0.01 ≤ c ≤ 1.00, 0.00 ≤ d ≤ 1.00 and 0.00 ≤ e ≤ 1.00, and n is a value determined by the atomic valences of the constituent elements of the composite oxide; an impregnation step of impregnating the composite oxide with a solution containing at least one specific element selected from the group consisting of tungsten, molybdenum, tellurium, niobium, vanadium, boron, bismuth, manganese, iron, antimony, phosphorus and rare earth elements to thereby obtain an impregnated composite oxide; and a second drying step of drying the impregnated composite oxide, wherein at least one of the impregnation step and the second drying step is a step of impregnating the composite oxide or drying the impregnated composite oxide while stirring by a stirring power per unit composite oxide volume given by following formula: Pv kW / m 3 = P kW / V m 3 wherein Pv represents the stirring power per unit composite oxide volume(kW/m 3); P represents the electric power (kW) used in the stirring time; and V represents the volume (m 3) of the composite oxide packed in a stirring apparatus; and Pv is 0.001 ≤ Pv ≤ 300, wherein the first drying step is a spray drying step, wherein the inlet port temperature of the drier is between 150 °C or higher and 300 °C or lower, and the outlet port temperature of the drier is 100 °C or higher and 160 °C or lower, in the calcination of the dried material, the heating is started from a temperature lower than 400 °C and is carried out continuously or stepwise up to a temperature in the range of 550 °C or higher and 800 °C or lower, and in the second drying step, the temperature of the composite oxide is 30 °C or higher and 650 °C or lower. a preparation step of dissolving or dispersing a raw material to thereby obtain a prepared raw material liquid; a first drying step of drying the prepared raw material liquid to thereby obtain a dried material; a calcination step of calcining the dried material to thereby obtain a composite oxide represented by following formula: Mo 1 V a Nb b A c X d Z e O n... wherein A represents at least one element selected from the group consisting of Sb and Te; X represents at least one element selected from the group consisting of W, Bi, Mn and Ti; and Z represents at least one element selected from the group consisting of La, Ce, Pr, Yb, Y, Sc, Sr and Ba; and a, b, c, d, e and n represent elemental ratios of the respective elements per one element of Mo and 0.01 ≤ a ≤ 1.00, 0.01 ≤ b ≤ 1.00, 0.01 ≤ c ≤ 1.00, 0.00 ≤ d ≤ 1.00 and 0.00 ≤ e ≤ 1.00, and n is a value determined by the atomic valences of the constituent elements of the composite oxide; an impregnation step of impregnating the composite oxide with a solution containing at least one specific element selected from the group consisting of tungsten, molybdenum, tellurium, niobium, vanadium, boron, bismuth, manganese, iron, antimony, phosphorus and rare earth elements to thereby obtain an impregnated composite oxide; and a second drying step of drying the impregnated composite oxide, wherein at least one of the impregnation step and the second drying step is a step of impregnating the composite oxide or drying the impregnated composite oxide while stirring by a stirring power per unit composite oxide volume given by following formula: Pv kW / m 3 = P kW / V m 3 wherein Pv represents the stirring power per unit composite oxide volume(kW/m 3); P represents the electric power (kW) used in the stirring time; and V represents the volume (m 3) of the composite oxide packed in a stirring apparatus; and Pv is 0.001 ≤ Pv ≤ 300, wherein the first drying step is a spray drying step, wherein the inlet port temperature of the drier is between 150 °C or higher and 300 °C or lower, and the outlet port temperature of the drier is 100 °C or higher and 160 °C or lower, in the calcination of the dried material, the heating is started from a temperature lower than 400 °C and is carried out continuously or stepwise up to a temperature in the range of 550 °C or higher and 800 °C or lower, and in the second drying step, the temperature of the composite oxide is 30 °C or higher and 650 °C or lower.