A method of producing a steel material, the method comprising: a step of analyzing, after secondary refining, an amount of Al 2 O 3 in the molten steel by spark discharge atomic emission spectroscopy; a step of adding Ca to molten steel with an amount of Ca adjusted within a range satisfying the formula below in accordance with the amount of Al 2 O 3 analyzed in the analyzing step; an intensity ratio computing step of determining aluminum/iron light emission intensity ratios of a plurality of discharge pulses; an alumina fraction computing step of computing an alumina fraction determined using the formula below; a step of arranging the light emission intensity ratios of the respective discharge pulses obtained in the intensity ratio computing step in ascending order, using a light emission intensity ratio at a certain position equal to or lower than 30% of the total number of discharge pulses as a representative aluminum intensity ratio, and then computing an alumina intensity ratio (= the alumina fraction × a representative aluminum intensity ratio) using a product of the alumina fraction computed in the alumina fraction computing step and the representative aluminum intensity ratio; and a quantitative step of computing the amount of alumina (in the steel) using a relational formula between the alumina intensity ratio and the amount of alumina (in the steel) determined by chemical analysis: 0.5 ≤ Ca ⋅ y / 100 − S ⋅ W / 100 ⋅ 40.08 / 32.07 56.08 40.08 A l 2 O 3 ⋅ W / 100 ≤ 1.5 where Ca is the amount [kg] of Ca added, y is an yield [%] of Ca, is a concentration [% by mass] of S in the steel before addition of Ca, [Al 2 O 3] is an amount [% by mass] of Al 2 O 3 in the steel before addition of Ca, and W is a weight [kg] of the molten steel; A l u m i n a fraction = N u m b e r o f d i s c h a r g e p u l s e s w i t h Al / Fe i n t e n s i t y r a t i o l a r g e r t h a n t h r e s h o l d v a l u e α / t o t a l n u m b e r o f pulses where the threshold value α is determined using a frequency distribution diagram having a horizontal axis representing the light emission intensity ratios for the discharge pulses and a vertical axis representing frequency, the threshold value α being a value obtained by multiplying a mode of the light emission intensity ratios by a factor of f 1 (1.5 ≤ f 1 ≤2.5). a step of analyzing, after secondary refining, an amount of Al 2 O 3 in the molten steel by spark discharge atomic emission spectroscopy; a step of adding Ca to molten steel with an amount of Ca adjusted within a range satisfying the formula below in accordance with the amount of Al 2 O 3 analyzed in the analyzing step; an intensity ratio computing step of determining aluminum/iron light emission intensity ratios of a plurality of discharge pulses; an alumina fraction computing step of computing an alumina fraction determined using the formula below; a step of arranging the light emission intensity ratios of the respective discharge pulses obtained in the intensity ratio computing step in ascending order, using a light emission intensity ratio at a certain position equal to or lower than 30% of the total number of discharge pulses as a representative aluminum intensity ratio, and then computing an alumina intensity ratio (= the alumina fraction × a representative aluminum intensity ratio) using a product of the alumina fraction computed in the alumina fraction computing step and the representative aluminum intensity ratio; and a quantitative step of computing the amount of alumina (in the steel) using a relational formula between the alumina intensity ratio and the amount of alumina (in the steel) determined by chemical analysis: 0.5 ≤ Ca ⋅ y / 100 − S ⋅ W / 100 ⋅ 40.08 / 32.07 56.08 40.08 A l 2 O 3 ⋅ W / 100 ≤ 1.5 where Ca is the amount [kg] of Ca added, y is an yield [%] of Ca, is a concentration [% by mass] of S in the steel before addition of Ca, [Al 2 O 3] is an amount [% by mass] of Al 2 O 3 in the steel before addition of Ca, and W is a weight [kg] of the molten steel; A l u m i n a fraction = N u m b e r o f d i s c h a r g e p u l s e s w i t h Al / Fe i n t e n s i t y r a t i o l a r g e r t h a n t h r e s h o l d v a l u e α / t o t a l n u m b e r o f pulses where the threshold value α is determined using a frequency distribution diagram having a horizontal axis representing the light emission intensity ratios for the discharge pulses and a vertical axis representing frequency, the threshold value α being a value obtained by multiplying a mode of the light emission intensity ratios by a factor of f 1 (1.5 ≤ f 1 ≤2.5). where Ca is the amount [kg] of Ca added, y is an yield [%] of Ca, is a concentration [% by mass] of S in the steel before addition of Ca, [Al 2 O 3] is an amount [% by mass] of Al 2 O 3 in the steel before addition of Ca, and W is a weight [kg] of the molten steel; A l u m i n a fraction = N u m b e r o f d i s c h a r g e p u l s e s w i t h Al / Fe i n t e n s i t y r a t i o l a r g e r t h a n t h r e s h o l d v a l u e α / t o t a l n u m b e r o f pulses where the threshold value α is determined using a frequency distribution diagram having a horizontal axis representing the light emission intensity ratios for the discharge pulses and a vertical axis representing frequency, the threshold value α being a value obtained by multiplying a mode of the light emission intensity ratios by a factor of f 1 (1.5 ≤ f 1 ≤2.5).