An electronic signature authentication system based on biometric information, comprising: an authentication server configured to register a public key of a signer (U PK ) generated based on biometric information for user identification (S520) and perform authentication of an electronic document (D) that is electronically signed with a private key of the signer (U SK ) generated based on the biometric information, and that is verified by using the public key of the signer (S915-S940); an electronic document device configured to request an electronic signature for the electronic document to a user device , extract encryption data (E1-E4) from data received from the user device (S225), and generate a final electronic file for storage (F) by combining the encryption data (E2-E5) with the electronic document (D) to transfer to the authentication server (S230); and the user device configured to register the biometric information for user identification of the signer and a handwritten signature for document confirmation entered from the signer (S125), generate the public key (U PK ) and the private key (U SK ) of the signer based on the registered biometric information for user identification (S130, S510), register the public key of the signer to the authentication server (S135, S515), receive a handwritten signature for document confirmation of the signer (S200) in response to a signature request from the electronic document device , determine whether the received handwritten signature for document confirmation matches the registered handwritten signature for document confirmation (S205), complete the input of the handwritten signature in a signature field in the electronic document to be signed (S200-S210), generate an electronic signature value (DS1-DS3) by using the private key of the signer (U SK ), and generate the encryption data (E1-E4) by encrypting the generated electronic signature value (S220). an authentication server configured to register a public key of a signer (U PK ) generated based on biometric information for user identification (S520) and perform authentication of an electronic document (D) that is electronically signed with a private key of the signer (U SK ) generated based on the biometric information, and that is verified by using the public key of the signer (S915-S940); an electronic document device configured to request an electronic signature for the electronic document to a user device , extract encryption data (E1-E4) from data received from the user device (S225), and generate a final electronic file for storage (F) by combining the encryption data (E2-E5) with the electronic document (D) to transfer to the authentication server (S230); and the user device configured to register the biometric information for user identification of the signer and a handwritten signature for document confirmation entered from the signer (S125), generate the public key (U PK ) and the private key (U SK ) of the signer based on the registered biometric information for user identification (S130, S510), register the public key of the signer to the authentication server (S135, S515), receive a handwritten signature for document confirmation of the signer (S200) in response to a signature request from the electronic document device , determine whether the received handwritten signature for document confirmation matches the registered handwritten signature for document confirmation (S205), complete the input of the handwritten signature in a signature field in the electronic document to be signed (S200-S210), generate an electronic signature value (DS1-DS3) by using the private key of the signer (U SK ), and generate the encryption data (E1-E4) by encrypting the generated electronic signature value (S220). <EOS>