The present invention provides an epoxy resin composition having a high heat resistance such as a thermal decomposition temperature, as well as a high adhesive strength, in particular inner layer adhesive strength, and also provides a prepreg, a laminate board and a multi-layer board using the composition. The epoxy resin composition according to the present invention contains an epoxy resin containing nitrogen and bromine in the molecule, a curing agent having a phenolic hydroxyl group, and a silane compound having no cure acceleration action and having reactivity with the epoxy resin. The bromine content in a resin component of the epoxy resin composition is 10 mass% or greater.