A spray ionization device , comprising: an outer tube including a gas channel through which a gas can flow, the outer tube including an ejection port covered with a porous member at one end; a first tube within the outer tube , the first tube including a first channel through which a first liquid can flow, the first tube including a first outlet for ejecting the first liquid at the one end; a second tube within the outer tube , the second tube including a second channel through which a second liquid can flow, the second tube including a second outlet for ejecting the second liquid at the one end; wherein the outer tube surrounds an outer circumferential surface of at least one of the first tube and the second tube with a gap, wherein the porous member is at a distance downstream of the first outlet and the second outlet at the one end; and an electrode arranged in at least one of the first channel and the second channel to reach the respective outlet, or through the gas channel to reach a mixing region upstream of the porous member between the first outlet or the second outlet and the porous member, or in at least one of the first channel and the second channel such that a tip of the electrode is provided so as to form a surface contiguous with an inner circumferential surface of the respective tube, or in at least one of the first channel and the second channel to include an annular member through an inside of which the respective liquid can flow, the electrode being arranged to apply voltage to at least one of the first liquid and the second liquid by a power source connected to the electrode , wherein the device is configured so that charged droplets generated by mixing the first liquid and the second liquid together with the gas are ejected from the ejection port . an outer tube including a gas channel through which a gas can flow, the outer tube including an ejection port covered with a porous member at one end; a first tube within the outer tube , the first tube including a first channel through which a first liquid can flow, the first tube including a first outlet for ejecting the first liquid at the one end; a second tube within the outer tube , the second tube including a second channel through which a second liquid can flow, the second tube including a second outlet for ejecting the second liquid at the one end; wherein the outer tube surrounds an outer circumferential surface of at least one of the first tube and the second tube with a gap, wherein the porous member is at a distance downstream of the first outlet and the second outlet at the one end; and an electrode arranged in at least one of the first channel and the second channel to reach the respective outlet, or through the gas channel to reach a mixing region upstream of the porous member between the first outlet or the second outlet and the porous member, or in at least one of the first channel and the second channel such that a tip of the electrode is provided so as to form a surface contiguous with an inner circumferential surface of the respective tube, or in at least one of the first channel and the second channel to include an annular member through an inside of which the respective liquid can flow, the electrode being arranged to apply voltage to at least one of the first liquid and the second liquid by a power source connected to the electrode , wherein the device is configured so that charged droplets generated by mixing the first liquid and the second liquid together with the gas are ejected from the ejection port . <EOS>