A copolycarbonate which contains a unit represented by the following formula and a unit represented by the following formula as main recurring units, the (A/B1) molar ratio of the unit and the unit being 80/20 to 95/5, and satisfies the following requirements (i) to (v): (R 1 is an alkylene group having 8 to 12 carbon atoms which may be substituted by an aromatic group having 6 to 12 carbon atoms.) (i) the specific viscosity measured from a 20°C methylene chloride solution should be 0.23 to 0.60; the specific viscosity being obtained from a solution prepared by dissolving 0.7 g of the copolycarbonate in 100 ml of methylene chloride at 20°C by using an Ostwald viscometer and calculated according to the following equation: Specific viscosity η sp = t − t 0 / t 0 wherein "to" is the number of seconds required for the dropping of methylene chloride and "t" is the number of seconds required for the dropping of a sample solution; (ii) the glass transition temperature should be 90 to 150°C; the glass transition temperature (Tg) being measured by DSC at a temperature elevation rate of 20°C/min; (iii) the saturation water absorption coefficient should be not more than 2.5 %; the water absorption coefficient (Wa) being obtained from the following equation by measuring the weight of a cast film having a thickness of 200 μm obtained by dissolving a polycarbonate resin pellet in methylene chloride and evaporating methylene chloride after it was dried at 100°C for 12 hours and immersed in 25°C water for 48 hours: Water absorption coefficient % = weight of resin after water absorption − weight of resin before water absorption / weight of resin before water absorption × 100; (iv) the pencil hardness should be at least F; the pencil hardness being such hardness that when the copolycarbonate is rubbed with a pencil having specific pencil hardness, no scratch mark is left, and the pencil hardness used in the surface hardness test of a film being measured in accordance with JIS K-5600; (v) the 50 % breaking energy measured by a falling weight impact test at -20°C should be not less than 20 J and the brittle fracture rate should be not more than 50 %; as determined using a 2 mm-thick square plate to carry out a low-temperature planar impact test 10 times at a testing temperature of -20°C, a testing speed of 7 m/sec, a striker diameter of 1.27 cm (1/2 inch) and a receptor diameter of 2.54 cm (1 inch) to evaluate the probability that the specimen becomes fragile and 50 % breaking energy (average value). (i) the specific viscosity measured from a 20°C methylene chloride solution should be 0.23 to 0.60; the specific viscosity being obtained from a solution prepared by dissolving 0.7 g of the copolycarbonate in 100 ml of methylene chloride at 20°C by using an Ostwald viscometer and calculated according to the following equation: Specific viscosity η sp = t − t 0 / t 0 wherein "to" is the number of seconds required for the dropping of methylene chloride and "t" is the number of seconds required for the dropping of a sample solution; (ii) the glass transition temperature should be 90 to 150°C; the glass transition temperature (Tg) being measured by DSC at a temperature elevation rate of 20°C/min; (iii) the saturation water absorption coefficient should be not more than 2.5 %; the water absorption coefficient (Wa) being obtained from the following equation by measuring the weight of a cast film having a thickness of 200 μm obtained by dissolving a polycarbonate resin pellet in methylene chloride and evaporating methylene chloride after it was dried at 100°C for 12 hours and immersed in 25°C water for 48 hours: Water absorption coefficient % = weight of resin after water absorption − weight of resin before water absorption / weight of resin before water absorption × 100; (iv) the pencil hardness should be at least F; the pencil hardness being such hardness that when the copolycarbonate is rubbed with a pencil having specific pencil hardness, no scratch mark is left, and the pencil hardness used in the surface hardness test of a film being measured in accordance with JIS K-5600; (v) the 50 % breaking energy measured by a falling weight impact test at -20°C should be not less than 20 J and the brittle fracture rate should be not more than 50 %; as determined using a 2 mm-thick square plate to carry out a low-temperature planar impact test 10 times at a testing temperature of -20°C, a testing speed of 7 m/sec, a striker diameter of 1.27 cm (1/2 inch) and a receptor diameter of 2.54 cm (1 inch) to evaluate the probability that the specimen becomes fragile and 50 % breaking energy (average value).