A retrieval device (12-h) that performs exact match search by secure computation in which m, n, t(i), and N are positive integers, i = 1,..., m, j = 1,..., N, n ≤ N, and t(i) ≤ N, the retrieval device (12-h) comprising: a storage (128-h) that stores concealed database [x 1],..., [x m] including a concealed search target word [x i] in which a search target word x i = (x i,1,..., x i,t(i),..., x i,N) is concealed, the search target word x i including t(i) pieces of characters x i,1,..., x i,t(i), wherein the search target word x i further includes N-t(i) pieces of null characters representing null values when t(i) < N holds; an input unit (1291-h) that receives an input of a concealed search word [k] in which a search word k = (k 1,..., k n,..., k N) is concealed, the search word k including n pieces of characters k 1,..., k n including a wildcard character; an equality determination unit (121-h) that obtains a concealed operation result [e i] in which an operation result e i = (e i,1,..., e i,N) is concealed, the operation result e i in which e i,j = a 1 is established when x i,j is k j, e i,j = a 0 is established when x i,j is not k j, and a 0 and a 1 are distinct predetermined elements, by secure computation using the concealed search target word [x i] and the concealed search word [k]; a wildcard determination unit (122-h) that obtains a concealed operation result [w] in which an operation result w = (w 1,..., w N) is concealed, the operation result w in which w j = b 1 is established when k j is the wildcard character, w j = b 0 is established when k j is not the wildcard character, and b 0 and b 1 are distinct predetermined elements, by secure computation using the concealed search word [k]; an OR operation unit (123-h) that obtains a concealed operation result [y i] in which an operation result y i = (y i,1,..., y i,N) is concealed, the operation result y i in which y i,j = d 1 is established when at least one of e i,j = a 1, w j = b 1 is satisfied and y i,j = d 0 is established when both of e i,j = a 0 and w j = b 0 are satisfied, and d 0 and d 1 are distinct predetermined elements, by secure computation using the concealed operation result [e i] and the concealed operation result [w]; and an AND operation unit (127-h) that obtains a concealed match determination result [z i] in which a match determination result z i is concealed, the match determination result z i in which z i = g 1 is established when y i,1 =... = y i,N = d 1 is satisfied, z i = g 0 is established when y i,1 =... = y i,N = d 1 is not satisfied, and g 0 and g 1 are distinct predetermined elements, by secure computation using the concealed operation result [y i], wherein [v] denotes the concealing of a value v by homomorphic encryption; or the retrieval device performs the secure computation in communication with H-1≥1 other retrieval devices and [v] denotes the concealing of a value v by secret sharing among the H retrieval devices. a storage (128-h) that stores concealed database [x 1],..., [x m] including a concealed search target word [x i] in which a search target word x i = (x i,1,..., x i,t(i),..., x i,N) is concealed, the search target word x i including t(i) pieces of characters x i,1,..., x i,t(i), wherein the search target word x i further includes N-t(i) pieces of null characters representing null values when t(i) < N holds; an input unit (1291-h) that receives an input of a concealed search word [k] in which a search word k = (k 1,..., k n,..., k N) is concealed, the search word k including n pieces of characters k 1,..., k n including a wildcard character; an equality determination unit (121-h) that obtains a concealed operation result [e i] in which an operation result e i = (e i,1,..., e i,N) is concealed, the operation result e i in which e i,j = a 1 is established when x i,j is k j, e i,j = a 0 is established when x i,j is not k j, and a 0 and a 1 are distinct predetermined elements, by secure computation using the concealed search target word [x i] and the concealed search word [k]; a wildcard determination unit (122-h) that obtains a concealed operation result [w] in which an operation result w = (w 1,..., w N) is concealed, the operation result w in which w j = b 1 is established when k j is the wildcard character, w j = b 0 is established when k j is not the wildcard character, and b 0 and b 1 are distinct predetermined elements, by secure computation using the concealed search word [k]; an OR operation unit (123-h) that obtains a concealed operation result [y i] in which an operation result y i = (y i,1,..., y i,N) is concealed, the operation result y i in which y i,j = d 1 is established when at least one of e i,j = a 1, w j = b 1 is satisfied and y i,j = d 0 is established when both of e i,j = a 0 and w j = b 0 are satisfied, and d 0 and d 1 are distinct predetermined elements, by secure computation using the concealed operation result [e i] and the concealed operation result [w]; and an AND operation unit (127-h) that obtains a concealed match determination result [z i] in which a match determination result z i is concealed, the match determination result z i in which z i = g 1 is established when y i,1 =... = y i,N = d 1 is satisfied, z i = g 0 is established when y i,1 =... = y i,N = d 1 is not satisfied, and g 0 and g 1 are distinct predetermined elements, by secure computation using the concealed operation result [y i], wherein [v] denotes the concealing of a value v by homomorphic encryption; or the retrieval device performs the secure computation in communication with H-1≥1 other retrieval devices and [v] denotes the concealing of a value v by secret sharing among the H retrieval devices.