A spray ionization device (10, 610, 710), comprising: a first tube including a first channel through which a liquid (Lf) can flow, the first tube including a first outlet for ejecting the liquid (Lf) at one end; a second tube (22, 42, 52, 122, 132, 142) surrounding the first tube with a gap and including a second channel (24, 124) through which a gas (Gf) can flow, the second tube (22, 42, 52, 122, 132, 142) including a second outlet (22a, 42a, 52a, 122a, 132a, 142a) at the one end, the second channel (24, 124) being defined by an outer circumferential surface of the first tube and an inner circumferential surface of the second tube (22, 42, 52, 122, 132, 142); and an electrode which extends within the first channel of the first tube from an opposite end to the one end, and is arranged so that a leading end is at the same position as the first outlet or further toward the opposite end than the first outlet, the electrode being capable of applying voltage to the liquid (Lf) by way of a power source connected to the electrode, wherein the second channel includes a first constriction portion, and a channel area of the second channel progressively decreases from the opposite end to the first constriction portion, at the one end, the second outlet (22a, 42a, 52a, 122a, 132a, 142a) is arranged further toward a tip than the first outlet, at least a portion of the inner circumferential surface of the second tube (22, 42, 52, 122, 132, 142) has a diameter that progressively decreases toward the second outlet (22a, 42a, 52a, 122a, 132a, 142a), and a diameter of the inner circumferential surface of the second outlet (22a, 42a, 52a, 122a, 132a, 142a) is equal to or greater than an opening diameter of the first outlet, and electrically charged droplets of the liquid (Lf) can be ejected from the second outlet (22a, 42a, 52a, 122a, 132a, 142a), the spray ionization device (10, 610, 710), further comprising: a third tube between the first tube and the second tube (122, 132, 142), the third tube surrounding the first tube and including a third outlet at the one end, characterized in that the second channel through which the gas (Gf) can flow is defined by an outer circumferential surface of the third tube and the inner circumferential surface of the second tube (122, 132, 142), at the one end, a tip of the third tube is arranged further toward the opposite end than the first outlet, the second channel includes a second constriction portion formed by a tip of the outer circumferential surface at the one end of the third tube and the inner circumferential surface of the second tube (122, 132, 142), and at the tip at the one end of the third tube, a gap between an inner circumferential surface of the third tube and the outer circumferential surface of the first tube is blocked by a blocking member. a second tube (22, 42, 52, 122, 132, 142) surrounding the first tube with a gap and including a second channel (24, 124) through which a gas (Gf) can flow, the second tube (22, 42, 52, 122, 132, 142) including a second outlet (22a, 42a, 52a, 122a, 132a, 142a) at the one end, the second channel (24, 124) being defined by an outer circumferential surface of the first tube and an inner circumferential surface of the second tube (22, 42, 52, 122, 132, 142); and an electrode which extends within the first channel of the first tube from an opposite end to the one end, and is arranged so that a leading end is at the same position as the first outlet or further toward the opposite end than the first outlet, the electrode being capable of applying voltage to the liquid (Lf) by way of a power source connected to the electrode, wherein the second channel includes a first constriction portion, and a channel area of the second channel progressively decreases from the opposite end to the first constriction portion, at the one end, the second outlet (22a, 42a, 52a, 122a, 132a, 142a) is arranged further toward a tip than the first outlet, at least a portion of the inner circumferential surface of the second tube (22, 42, 52, 122, 132, 142) has a diameter that progressively decreases toward the second outlet (22a, 42a, 52a, 122a, 132a, 142a), and a diameter of the inner circumferential surface of the second outlet (22a, 42a, 52a, 122a, 132a, 142a) is equal to or greater than an opening diameter of the first outlet, and electrically charged droplets of the liquid (Lf) can be ejected from the second outlet (22a, 42a, 52a, 122a, 132a, 142a), the spray ionization device (10, 610, 710), further comprising: a third tube between the first tube and the second tube (122, 132, 142), the third tube surrounding the first tube and including a third outlet at the one end, characterized in that the second channel through which the gas (Gf) can flow is defined by an outer circumferential surface of the third tube and the inner circumferential surface of the second tube (122, 132, 142), at the one end, a tip of the third tube is arranged further toward the opposite end than the first outlet, the second channel includes a second constriction portion formed by a tip of the outer circumferential surface at the one end of the third tube and the inner circumferential surface of the second tube (122, 132, 142), and at the tip at the one end of the third tube, a gap between an inner circumferential surface of the third tube and the outer circumferential surface of the first tube is blocked by a blocking member.