A hydrosilylation reaction catalyst which is prepared from: (i) a metal salt compound having the formula: M a b c wherein (a) M is Fe, Co or Ni, a is 1, b is 2, and c is 0; (b) M is Rh, a is 2, b is 4, and c is 0; or (c) M is Ru, a is 2, b is 4, and c is 1, X is a halogen atom, L is a monovalent organic group of at least one type selected from the formulae and when M is Fe, Co, Ni, Rh or Ru, or -OCO-2-thienyl group when M is Fe, -O-R 1 -OCO-R 1 wherein each R 1 independently is a C 1 -C 30 monovalent hydrocarbon group, which may be substituted with halogen atoms, or a monovalent organic group having the formula: - p -R 2 wherein A is a C 1 -C 30 divalent hydrocarbon group, p is an integer of 0 or 1, satisfying p = 0 or 1 when L is a monovalent organic group having formula, and p = 1 when L is a monovalent organic group having formula, R 2 is a group having the formula: -{Si(R 3) 2 -R 4} s -Si(R 3) d {[(OSi(R 3) 2)] f -R 3} e wherein each R 3 independently is a C 1 -C 20 alkyl group, C 1 -C 20 alkoxy group, C 6 -C 20 aryl group or C 7 -C 20 aralkyl group, which may be substituted with halogen atoms, R 4 is a C 1 -C 10 divalent hydrocarbon group, s is an integer of 0 or 1, d is an integer of 0 to 3, e is an integer of 0 to 3, satisfying d+e = 3, and f is an integer of 1, and (ii) an isocyanide compound having the formula: Y- q wherein Y is a C 1 -C 30 hydrocarbon group which may be substituted with halogen atoms, and q is an integer of 1 to 3. (i) a metal salt compound having the formula: M a b c wherein (a) M is Fe, Co or Ni, a is 1, b is 2, and c is 0; (b) M is Rh, a is 2, b is 4, and c is 0; or (c) M is Ru, a is 2, b is 4, and c is 1, X is a halogen atom, L is a monovalent organic group of at least one type selected from the formulae and when M is Fe, Co, Ni, Rh or Ru, or -OCO-2-thienyl group when M is Fe, -O-R 1 -OCO-R 1 wherein each R 1 independently is a C 1 -C 30 monovalent hydrocarbon group, which may be substituted with halogen atoms, or a monovalent organic group having the formula: - p -R 2 wherein A is a C 1 -C 30 divalent hydrocarbon group, p is an integer of 0 or 1, satisfying p = 0 or 1 when L is a monovalent organic group having formula, and p = 1 when L is a monovalent organic group having formula, R 2 is a group having the formula: -{Si(R 3) 2 -R 4} s -Si(R 3) d {[(OSi(R 3) 2)] f -R 3} e wherein each R 3 independently is a C 1 -C 20 alkyl group, C 1 -C 20 alkoxy group, C 6 -C 20 aryl group or C 7 -C 20 aralkyl group, which may be substituted with halogen atoms, R 4 is a C 1 -C 10 divalent hydrocarbon group, s is an integer of 0 or 1, d is an integer of 0 to 3, e is an integer of 0 to 3, satisfying d+e = 3, and f is an integer of 1, and X is a halogen atom, L is a monovalent organic group of at least one type selected from the formulae and when M is Fe, Co, Ni, Rh or Ru, or -OCO-2-thienyl group when M is Fe, -O-R 1 -OCO-R 1 wherein each R 1 independently is a C 1 -C 30 monovalent hydrocarbon group, which may be substituted with halogen atoms, or a monovalent organic group having the formula: - p -R 2 wherein A is a C 1 -C 30 divalent hydrocarbon group, p is an integer of 0 or 1, satisfying p = 0 or 1 when L is a monovalent organic group having formula, and p = 1 when L is a monovalent organic group having formula, R 2 is a group having the formula: -{Si(R 3) 2 -R 4} s -Si(R 3) d {[(OSi(R 3) 2)] f -R 3} e wherein each R 3 independently is a C 1 -C 20 alkyl group, C 1 -C 20 alkoxy group, C 6 -C 20 aryl group or C 7 -C 20 aralkyl group, which may be substituted with halogen atoms, R 4 is a C 1 -C 10 divalent hydrocarbon group, s is an integer of 0 or 1, d is an integer of 0 to 3, e is an integer of 0 to 3, satisfying d+e = 3, and f is an integer of 1, and p is an integer of 0 or 1, satisfying p = 0 or 1 when L is a monovalent organic group having formula, and p = 1 when L is a monovalent organic group having formula, R 2 is a group having the formula: -{Si(R 3) 2 -R 4} s -Si(R 3) d {[(OSi(R 3) 2)] f -R 3} e wherein each R 3 independently is a C 1 -C 20 alkyl group, C 1 -C 20 alkoxy group, C 6 -C 20 aryl group or C 7 -C 20 aralkyl group, which may be substituted with halogen atoms, R 4 is a C 1 -C 10 divalent hydrocarbon group, s is an integer of 0 or 1, d is an integer of 0 to 3, e is an integer of 0 to 3, satisfying d+e = 3, and f is an integer of 1, and (ii) an isocyanide compound having the formula: Y- q wherein Y is a C 1 -C 30 hydrocarbon group which may be substituted with halogen atoms, and q is an integer of 1 to 3.