A production process for an optical material using, as raw materials thereof, a compound (a), a compound (b), a compound (c), (d) and a compound (e) as shown below, the process comprising the following steps 1 to 5: Step 1: a step of obtaining a first liquid by dissolving the compound (b) in the compound (a); Step 2: a step of obtaining a second liquid by adding the compound (e) mixed with a portion of the compound (d) to the first liquid obtained in Step 1 and mixing the compound (e) mixed with a portion of the compound (d) with the first liquid; Step 3: a step of obtaining a reaction mixture by adding the compound (c) to the second liquid obtained in Step 2 and reacting the resulting mixture under reduced pressure; Step 4: a step of obtaining a resin composition for an optical material by adding the remainder of the compound (d) to the reaction mixture obtained in Step 3 and mixing the remainder of the compound (d) with the reaction mixture; and Step 5: a step of obtaining an optical material by casting and polymerizing the resin composition for an optical material obtained in Step 4; wherein, compound (a) is a compound having the structure represented by the following formula: (where, m represents an integer of 0 to 4 and n represents an integer of 0 to 2); compound (b) is sulfur; compound (c) is at least one type of compound selected from the group consisting of m-xylylene diiisocyanate, p-xylylene diisocyanate, m-tetramethylxylylene diisocyanate and p-tetramethylxylylene diisocyanate; compound (d) is at least one type of compound selected from the group consisting of bis(2-mercaptoethyl) sulfide, bis(2,3-dimercaptopropyl) sulfide, 1,2-bis(2-mercaptoethylthio) ethane, 2-(2-mercaptoethylthio)-1,3-dimercaptopropane, 2,5-bis(mercaptomethyl)-1,4-dithiane, 2,5-bis(2-mercaptoethyl)-1,4-dithane, 2,5-bis(mercaptomethyl)-1-thiane, 2,5-bis (2-mercaptoethyl-1-thiane, bis(4-mercaptophenyl) sulfide, bis(4-mercaptomethylphenyl) sulfide and 3,4-thiophenedithiol; and compound (e) is at least one type of compound selected from the group consisting of pentaerythritol tetrakismercaptopropionate, pentaerythritol tetrakisthioglycolate, tetrakis(mercaptomethyl) methane, tetrakis(mercaptomethylthiomethyl) methane, tetrakis(2-mercaptoethylthiomethyl) methane and tetrakis(3-mercaptothiomethyl) methane. Step 1: a step of obtaining a first liquid by dissolving the compound (b) in the compound (a); Step 2: a step of obtaining a second liquid by adding the compound (e) mixed with a portion of the compound (d) to the first liquid obtained in Step 1 and mixing the compound (e) mixed with a portion of the compound (d) with the first liquid; Step 3: a step of obtaining a reaction mixture by adding the compound (c) to the second liquid obtained in Step 2 and reacting the resulting mixture under reduced pressure; Step 4: a step of obtaining a resin composition for an optical material by adding the remainder of the compound (d) to the reaction mixture obtained in Step 3 and mixing the remainder of the compound (d) with the reaction mixture; and Step 5: a step of obtaining an optical material by casting and polymerizing the resin composition for an optical material obtained in Step 4; wherein, compound (a) is a compound having the structure represented by the following formula: (where, m represents an integer of 0 to 4 and n represents an integer of 0 to 2); compound (b) is sulfur; compound (c) is at least one type of compound selected from the group consisting of m-xylylene diiisocyanate, p-xylylene diisocyanate, m-tetramethylxylylene diisocyanate and p-tetramethylxylylene diisocyanate; compound (d) is at least one type of compound selected from the group consisting of bis(2-mercaptoethyl) sulfide, bis(2,3-dimercaptopropyl) sulfide, 1,2-bis(2-mercaptoethylthio) ethane, 2-(2-mercaptoethylthio)-1,3-dimercaptopropane, 2,5-bis(mercaptomethyl)-1,4-dithiane, 2,5-bis(2-mercaptoethyl)-1,4-dithane, 2,5-bis(mercaptomethyl)-1-thiane, 2,5-bis (2-mercaptoethyl-1-thiane, bis(4-mercaptophenyl) sulfide, bis(4-mercaptomethylphenyl) sulfide and 3,4-thiophenedithiol; and compound (e) is at least one type of compound selected from the group consisting of pentaerythritol tetrakismercaptopropionate, pentaerythritol tetrakisthioglycolate, tetrakis(mercaptomethyl) methane, tetrakis(mercaptomethylthiomethyl) methane, tetrakis(2-mercaptoethylthiomethyl) methane and tetrakis(3-mercaptothiomethyl) methane. compound (a) is a compound having the structure represented by the following formula: (where, m represents an integer of 0 to 4 and n represents an integer of 0 to 2); compound (b) is sulfur; compound (c) is at least one type of compound selected from the group consisting of m-xylylene diiisocyanate, p-xylylene diisocyanate, m-tetramethylxylylene diisocyanate and p-tetramethylxylylene diisocyanate; compound (d) is at least one type of compound selected from the group consisting of bis(2-mercaptoethyl) sulfide, bis(2,3-dimercaptopropyl) sulfide, 1,2-bis(2-mercaptoethylthio) ethane, 2-(2-mercaptoethylthio)-1,3-dimercaptopropane, 2,5-bis(mercaptomethyl)-1,4-dithiane, 2,5-bis(2-mercaptoethyl)-1,4-dithane, 2,5-bis(mercaptomethyl)-1-thiane, 2,5-bis (2-mercaptoethyl-1-thiane, bis(4-mercaptophenyl) sulfide, bis(4-mercaptomethylphenyl) sulfide and 3,4-thiophenedithiol; and compound (e) is at least one type of compound selected from the group consisting of pentaerythritol tetrakismercaptopropionate, pentaerythritol tetrakisthioglycolate, tetrakis(mercaptomethyl) methane, tetrakis(mercaptomethylthiomethyl) methane, tetrakis(2-mercaptoethylthiomethyl) methane and tetrakis(3-mercaptothiomethyl) methane.