A plasma device, comprising: a discharge space in which process gas flows, the process gas being a gas for generating plasma; a dielectric barrier discharger configured to perform dielectric barrier discharge on the process gas in the discharge space; and an arc discharger configured to perform arc discharge on the process gas and provided downstream from the dielectric barrier discharger in the direction in which the process gas in the discharge space flows, and the dielectric barrier discharger comprises first electrodes (29, 30) which are a pair of electrodes (29, 30), extending in the direction of flow of the process gas and spaced apart from each other in the direction (x) intersecting the direction of flow of the process gas; the arc discharger comprises second electrodes (27, 28) which are a pair of electrodes (27, 28), extending in the direction of flow of the process gas and spaced apart from each other in the direction intersecting the direction of flow of the process gas, wherein the arc discharge occurs between downstream end portions (27s, 28s) of the pair of the electrode rods (27, 28); and the first electrodes (29, 30) correspond to electrode holders (29, 30) and the second electrodes (27, 28) correspond to electrode rods (27, 28), wherein each of the electrode holders (29, 30) is made of a conductive material and the electrode rods (27, 28) are fixed to the electrode holders (29, 30), respectively, such that current can pass from each of the electrode holders (29, 30) to the respective rod (27, 28), and the dielectric barrier discharger comprises a dielectric barrier disposed between the pair of first electrodes (29, 30), wherein the dielectric barrier is composed of a pair of electrode covers (34, 36) covering each of the pair of first electrodes (29, 30), and there is no member made of dielectric between the pair of electrode covers (34, 36). a discharge space in which process gas flows, the process gas being a gas for generating plasma; a dielectric barrier discharger configured to perform dielectric barrier discharge on the process gas in the discharge space; and an arc discharger configured to perform arc discharge on the process gas and provided downstream from the dielectric barrier discharger in the direction in which the process gas in the discharge space flows, and the dielectric barrier discharger comprises first electrodes (29, 30) which are a pair of electrodes (29, 30), extending in the direction of flow of the process gas and spaced apart from each other in the direction (x) intersecting the direction of flow of the process gas; the arc discharger comprises second electrodes (27, 28) which are a pair of electrodes (27, 28), extending in the direction of flow of the process gas and spaced apart from each other in the direction intersecting the direction of flow of the process gas, wherein the arc discharge occurs between downstream end portions (27s, 28s) of the pair of the electrode rods (27, 28); and the first electrodes (29, 30) correspond to electrode holders (29, 30) and the second electrodes (27, 28) correspond to electrode rods (27, 28), wherein each of the electrode holders (29, 30) is made of a conductive material and the electrode rods (27, 28) are fixed to the electrode holders (29, 30), respectively, such that current can pass from each of the electrode holders (29, 30) to the respective rod (27, 28), and the dielectric barrier discharger comprises a dielectric barrier disposed between the pair of first electrodes (29, 30), wherein the dielectric barrier is composed of a pair of electrode covers (34, 36) covering each of the pair of first electrodes (29, 30), and there is no member made of dielectric between the pair of electrode covers (34, 36).