The invention aims to provide a prepreg that has high processability and laminating performance and to provide a method to produce such a prepreg in an industrially advantageous way. A prepreg comprising at least the components [A] to [E] given below, having a structure incorporating a first layer composed mainly of the component [A] and a first epoxy resin composition that contains the components [B] to [D] but is substantially free of the component [E] and a second layer composed mainly of a second epoxy resin composition that contains the components [B] to [E] and disposed adjacent to each surface of the first layer,
the second epoxy resin composition being characterized in that its component [D] has a weight-average molecular weight of 2,000 to 30,000 g/mol and accounts for 5 to 15 parts by mass relative to the total quantity of its components [B] to [E], which accounts for 100 parts by mass, and also characterized by having a storage elastic modulus G' at 25°C of 8.0 × 10 5 to 6.0 × 10 6 Pa as measured at an angular frequency of 3.14 rad/s, giving a value of 0.085 or more as calculated by the equation (1) given below, and showing a glass transition temperature of -10°C or more and less than 7°C as measured by differential scanning calorimetry (DSC),
and the component [D] contained therein accounting for 1 part by mass or more and less than 10 parts by mass relative to the total quantity of the first epoxy resin composition and the second epoxy resin composition, which accounts for 100 parts by mass:
[A] carbon fiber,
[B] epoxy resin,
[C] curing agent,
[D] thermoplastic resin, and
[E] particles containing a thermoplastic resin as primary component and having a volume-average particle diameter of 5 to 50 µm.
[Mathematical formula 1] log 10 G ′ Pa at 25 ° C − log 10 G ′ Pa at 40 ° C 15