A secure computation apparatus (12 m, 22 m, 32 m, 42 m) comprising: a first check bit string acquiring part (125 m, 225 m, 325 m) adapted to obtain, using a secret sharing value of a value represented by a first target bit string that corresponds to a null value when a most significant bit is 1 and corresponds to a real number when the most significant bit is 0, a secret sharing value of a value represented by a first check bit string obtained by setting a value of the most significant bit of the first target bit string to a value of a first check bit lower than the most significant bit; and a first null value checking part (126 m, 226 m, 326 m) adapted to obtain secret sharing values of bit values of a least significant bit to the first check bit of the first check bit string using the secret sharing value of the value represented by the first check bit string, characterized in that: N is an integer equal to or larger than 2; P=2 N -1 is satisfied; L is an integer satisfying 0≤L≤N-u'; u' is a positive integer equal to or larger than 2 and equal to or smaller than N; and Xis an integer satisfying -2 L ≤X≤2 N-1 -2 L -1; Tis an integer satisfying 1≤T<N; the first target bit string is a string constituted by N bits; a value represented by the first target bit string corresponding to a null value is Y={2 L +(P+1)/2} mod P; a value represented by the first target bit string corresponding to X that is an integer equal to or larger than 0 is Y=(2 L +X) mod P; a value represented by the first target bit string corresponding to X that is a negative integer is Y=(P+2 L +X) mod P; the first check bit string is V=2 T ×Y mod P; and the first check bit is the T-th bit from the least significant bit. a first check bit string acquiring part (125 m, 225 m, 325 m) adapted to obtain, using a secret sharing value of a value represented by a first target bit string that corresponds to a null value when a most significant bit is 1 and corresponds to a real number when the most significant bit is 0, a secret sharing value of a value represented by a first check bit string obtained by setting a value of the most significant bit of the first target bit string to a value of a first check bit lower than the most significant bit; and a first null value checking part (126 m, 226 m, 326 m) adapted to obtain secret sharing values of bit values of a least significant bit to the first check bit of the first check bit string using the secret sharing value of the value represented by the first check bit string, characterized in that: N is an integer equal to or larger than 2; P=2 N -1 is satisfied; L is an integer satisfying 0≤L≤N-u'; u' is a positive integer equal to or larger than 2 and equal to or smaller than N; and Xis an integer satisfying -2 L ≤X≤2 N-1 -2 L -1; Tis an integer satisfying 1≤T<N; the first target bit string is a string constituted by N bits; a value represented by the first target bit string corresponding to a null value is Y={2 L +(P+1)/2} mod P; a value represented by the first target bit string corresponding to X that is an integer equal to or larger than 0 is Y=(2 L +X) mod P; a value represented by the first target bit string corresponding to X that is a negative integer is Y=(P+2 L +X) mod P; the first check bit string is V=2 T ×Y mod P; and the first check bit is the T-th bit from the least significant bit. N is an integer equal to or larger than 2; P=2 N -1 is satisfied; L is an integer satisfying 0≤L≤N-u'; u' is a positive integer equal to or larger than 2 and equal to or smaller than N; and Xis an integer satisfying -2 L ≤X≤2 N-1 -2 L -1; Tis an integer satisfying 1≤T<N; the first target bit string is a string constituted by N bits; a value represented by the first target bit string corresponding to a null value is Y={2 L +(P+1)/2} mod P; a value represented by the first target bit string corresponding to X that is an integer equal to or larger than 0 is Y=(2 L +X) mod P; a value represented by the first target bit string corresponding to X that is a negative integer is Y=(P+2 L +X) mod P; the first check bit string is V=2 T ×Y mod P; and the first check bit is the T-th bit from the least significant bit.