A vacuum device comprising: a vacuum unit for sucking air from inside a packing bag through a check valve of the packing bag to evacuate the packing bag; and a clamping unit provided at the vacuum unit for clamping the packing bag such that in use the check valve of the packing bag airtightly communicates with an air suction part of the vacuum unit, the clamping unit includes: a first support plate having a connection hole to which the air suction part is connected; and a second support plate connected to be in close contact with the first support plate, wherein when the first support plate is in use moved to the first plate to press the second support plate, the check valve of the packing bag positioned between the first support plate and the second support plate airtightly communicates with the connection hole, the device characterised by an operation unit installed on one side portion of the vacuum unit and electrically associated with the vacuum unit to sense clamping of the packing bag by the clamping unit to operate the vacuum unit, wherein the operation unit includes a sensing unit sensing movement of the first support plate to the second support plate or sensing the packing bag disposed between the first support plate and the second support plate when the first support plate is moved to the second support plate to press the second support plate, wherein the sensing unit in use protrudes and moves upon being pushed by the packing bag disposed between the first support plate and the second support plate, when the first support plate is moved to the second support plate to press the second support plate. a vacuum unit for sucking air from inside a packing bag through a check valve of the packing bag to evacuate the packing bag; and a clamping unit provided at the vacuum unit for clamping the packing bag such that in use the check valve of the packing bag airtightly communicates with an air suction part of the vacuum unit, the clamping unit includes: a first support plate having a connection hole to which the air suction part is connected; and a second support plate connected to be in close contact with the first support plate, wherein when the first support plate is in use moved to the first plate to press the second support plate, the check valve of the packing bag positioned between the first support plate and the second support plate airtightly communicates with the connection hole, the device characterised by an operation unit installed on one side portion of the vacuum unit and electrically associated with the vacuum unit to sense clamping of the packing bag by the clamping unit to operate the vacuum unit, wherein the operation unit includes a sensing unit sensing movement of the first support plate to the second support plate or sensing the packing bag disposed between the first support plate and the second support plate when the first support plate is moved to the second support plate to press the second support plate, wherein the sensing unit in use protrudes and moves upon being pushed by the packing bag disposed between the first support plate and the second support plate, when the first support plate is moved to the second support plate to press the second support plate. a first support plate having a connection hole to which the air suction part is connected; and a second support plate connected to be in close contact with the first support plate, wherein when the first support plate is in use moved to the first plate to press the second support plate, the check valve of the packing bag positioned between the first support plate and the second support plate airtightly communicates with the connection hole, the device characterised by an operation unit installed on one side portion of the vacuum unit and electrically associated with the vacuum unit to sense clamping of the packing bag by the clamping unit to operate the vacuum unit, wherein the operation unit includes a sensing unit sensing movement of the first support plate to the second support plate or sensing the packing bag disposed between the first support plate and the second support plate when the first support plate is moved to the second support plate to press the second support plate, wherein the sensing unit in use protrudes and moves upon being pushed by the packing bag disposed between the first support plate and the second support plate, when the first support plate is moved to the second support plate to press the second support plate. wherein when the first support plate is in use moved to the first plate to press the second support plate, the check valve of the packing bag positioned between the first support plate and the second support plate airtightly communicates with the connection hole, the device characterised by an operation unit installed on one side portion of the vacuum unit and electrically associated with the vacuum unit to sense clamping of the packing bag by the clamping unit to operate the vacuum unit, wherein the operation unit includes a sensing unit sensing movement of the first support plate to the second support plate or sensing the packing bag disposed between the first support plate and the second support plate when the first support plate is moved to the second support plate to press the second support plate, wherein the sensing unit in use protrudes and moves upon being pushed by the packing bag disposed between the first support plate and the second support plate, when the first support plate is moved to the second support plate to press the second support plate.