A catalyst for polymerization of olefin, containing a metal complex represented by formula (in the formula, M represents a metal atom of group 10 element in the periodic system; X represents a phosphorous atom or an arsenic (As) atom; Y 1 represents a bivalent hydrocarbon group having 1 to 70 carbon atoms which is substituted by at least one silyl group and may be substituted by one or more groups selected from a halogen atom, silyl group, alkoxy group and aryloxy group; Q represents a bivalent group indicated in the brackets of Y 1 [-S(=O) 2 -O-]M, Y 1 [-C(=O)-O-]M, Y 1 [-P(=O)(-OH)-O-]M or Y 1 [-S-]M (Y 1 and M at the beginning and at the end of the formulae are described to show the coupling direction of the groups); R 5 represents a substituent group selected from a group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted by a halogen atom, a hydrocarbon group having 2 to 30 carbon atoms substituted by an alkoxy group having 1 to 10 carbon atoms, a hydrocarbon group having 7 to 30 carbon atoms substituted by an aryloxy group having 6 to 20 carbon atoms, a hydrocarbon group having 3 to 30 carbon atoms substituted by an amide group having 2 to 10 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, and an acyloxy group having 2 to 10 carbon atoms; R 6 and R 7 independently represent a hydrogen atom, alkoxy group, aryloxy group, silyl group, amino group or hydrocarbon group having 1 to 120 carbon atoms which may be substituted by one or more groups selected from a halogen atom, alkoxy group and aryloxy group; and at least one of R 6 and R 7 represents an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 4 to 106 carbon atoms, R 6 or R 7 may bond to Y 1 to form a ring structure, L represents an electron-donating ligand and q is 0, 1/2, 1 or 2). (in the formula, M represents a metal atom of group 10 element in the periodic system; X represents a phosphorous atom or an arsenic (As) atom; Y 1 represents a bivalent hydrocarbon group having 1 to 70 carbon atoms which is substituted by at least one silyl group and may be substituted by one or more groups selected from a halogen atom, silyl group, alkoxy group and aryloxy group; Q represents a bivalent group indicated in the brackets of Y 1 [-S(=O) 2 -O-]M, Y 1 [-C(=O)-O-]M, Y 1 [-P(=O)(-OH)-O-]M or Y 1 [-S-]M (Y 1 and M at the beginning and at the end of the formulae are described to show the coupling direction of the groups); R 5 represents a substituent group selected from a group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted by a halogen atom, a hydrocarbon group having 2 to 30 carbon atoms substituted by an alkoxy group having 1 to 10 carbon atoms, a hydrocarbon group having 7 to 30 carbon atoms substituted by an aryloxy group having 6 to 20 carbon atoms, a hydrocarbon group having 3 to 30 carbon atoms substituted by an amide group having 2 to 10 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, and an acyloxy group having 2 to 10 carbon atoms; R 6 and R 7 independently represent a hydrogen atom, alkoxy group, aryloxy group, silyl group, amino group or hydrocarbon group having 1 to 120 carbon atoms which may be substituted by one or more groups selected from a halogen atom, alkoxy group and aryloxy group; and at least one of R 6 and R 7 represents an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 4 to 106 carbon atoms, R 6 or R 7 may bond to Y 1 to form a ring structure, L represents an electron-donating ligand and q is 0, 1/2, 1 or 2).