The bytecode processing device includes a branch target buffer including a tag field, a target address field corresponding to the tag field and an operation code bit field for representing whether a value stored in the tag field is an operation code, a bytecode fetch unit configured to fetch a bytecode including an operation code, an operation code extraction unit configured to extract the operation code from the bytecode, a branch target buffer search unit configured to perform a search to determine whether the extracted operation code exists in the tag field of the branch target buffer, and if the operation code exists in the tag field, extract a target address corresponding to the operation code from the target address field, and a bytecode execution unit configured to execute the bytecode by branching to the target address.