A silane compound of the following formula (1) having two or more protected functional groups A-R—Si(CH3)nX3-n  (1) wherein A represents a group of the following formula wherein R1, R2 and R3 each independently represent a monovalent hydrocarbon group having 1 to 10 carbon atoms, a is an integer of 1 to 10, and b is an integer of 1 to 10, or wherein R1, R2 and R3 are as defined above, R represents a linear or branched, divalent hydrocarbon group having 2 to 10 carbon atoms, X represents a halogen atom or an organoxy group having 1 to 10 carbon atoms, and n is 0, 1 or 2 is prevented from the reaction of the functional groups per self when undergoing modification or treatment. When the protection is removed after introduction of the protected functional groups, quantitative and efficient introduction of the two or more functional groups is ensured, resulting in more developed effects of modification and addition.