A tuning fork crystal oscillation plate (1, 21, 31, 41) comprising: a tuning fork crystal oscillation piece (1a, 31a) including a base with a substantially rectangular shape when seen from the top, and at least two oscillation arms (3a, 3b, 23a, 23b, 33a, 33b, 43a, 43b) extending in the same direction from one side of said base and having substantially rectangular shapes when seen from the top, said at least two oscillation arms including first and second oscillation arms; first and second grooves (4a, 4b) which are respectively formed only in a front main surface of said first oscillation arm and a front main surface of said second oscillation arm on the same side, said first groove and said second groove extending from a boundary line of said base with said first and second oscillation arms toward distal ends of said first oscillation arm and said second oscillation arm, said first groove and said second groove having a length that falls within a range of 50% inclusive, 70% exclusive, of the length of said first oscillation arm and said second oscillation arm, and said first groove and said second groove having a depth that falls within a range of 50% to 90%, both inclusive, of the thickness of said tuning fork crystal oscillation piece; first and second groove electrodes (6a, 6b) which are formed on inner surfaces of said first and second grooves, respectively, first side surface electrodes (8a, 8b) which are formed on two side surfaces, respectively, of said first oscillation arm; and second side surface electrodes (9a, 9b) which are formed on two side surfaces, respectively, of said second oscillation arm, characterized in that said first groove electrode is connected to said second side surface electrodes to constitute one terminal, and said second groove electrode is connected to said first side surface electrodes to constitute the other terminal, the tuning fork crystal oscillation plate further comprising: a first distal end electrode formed on a rear main surface of a distal end of said first oscillation arm and connected to said second groove electrode together with said first side surface electrodes; and a second distal end electrode formed on a rear main surface of a distal end of said second oscillation arm and connected to said first groove electrode together with said second side surface electrodes, wherein said first distal end electrode and said second distal end electrode are configured to adjust the resonant frequency of said tuning fork crystal oscillation plate. a tuning fork crystal oscillation piece (1a, 31a) including a base with a substantially rectangular shape when seen from the top, and at least two oscillation arms (3a, 3b, 23a, 23b, 33a, 33b, 43a, 43b) extending in the same direction from one side of said base and having substantially rectangular shapes when seen from the top, said at least two oscillation arms including first and second oscillation arms; first and second grooves (4a, 4b) which are respectively formed only in a front main surface of said first oscillation arm and a front main surface of said second oscillation arm on the same side, said first groove and said second groove extending from a boundary line of said base with said first and second oscillation arms toward distal ends of said first oscillation arm and said second oscillation arm, said first groove and said second groove having a length that falls within a range of 50% inclusive, 70% exclusive, of the length of said first oscillation arm and said second oscillation arm, and said first groove and said second groove having a depth that falls within a range of 50% to 90%, both inclusive, of the thickness of said tuning fork crystal oscillation piece; first and second groove electrodes (6a, 6b) which are formed on inner surfaces of said first and second grooves, respectively, first side surface electrodes (8a, 8b) which are formed on two side surfaces, respectively, of said first oscillation arm; and second side surface electrodes (9a, 9b) which are formed on two side surfaces, respectively, of said second oscillation arm, characterized in that said first groove electrode is connected to said second side surface electrodes to constitute one terminal, and said second groove electrode is connected to said first side surface electrodes to constitute the other terminal, the tuning fork crystal oscillation plate further comprising: a first distal end electrode formed on a rear main surface of a distal end of said first oscillation arm and connected to said second groove electrode together with said first side surface electrodes; and a second distal end electrode formed on a rear main surface of a distal end of said second oscillation arm and connected to said first groove electrode together with said second side surface electrodes, wherein said first distal end electrode and said second distal end electrode are configured to adjust the resonant frequency of said tuning fork crystal oscillation plate. a first distal end electrode formed on a rear main surface of a distal end of said first oscillation arm and connected to said second groove electrode together with said first side surface electrodes; and a second distal end electrode formed on a rear main surface of a distal end of said second oscillation arm and connected to said first groove electrode together with said second side surface electrodes, wherein said first distal end electrode and said second distal end electrode are configured to adjust the resonant frequency of said tuning fork crystal oscillation plate.