Material of interlayer and composite laminates

There is provided an intermediate layer material including a curing type resin composition and a fiber base material, to be used to form an intermediate layer of a composite laminate, wherein a cured material obtained by curing the intermediate layer material at a temperature of 180° C. has such properties as (i) a planar linear expansion coefficient (α1) equal to or lower than 20 ppm/° C., in a range equal to or higher than 25° C. and equal to or lower than a glass transition temperature (Tg); and (ii) a Barcol hardness equal to or more than 40 and equal to or less than 65, at 25° C.