A centrifugal force-based microfluidic device (100, 101, 102, 200) comprising: a platform, which can be rotated; a sample injection hole (31, 131), which is disposed at one side of the platform; a sample separation unit (40, 140) of which one end is connected to the sample injection hole (31, 131), and which is extended toward the outside of the platform so as to provide a space in which a sample, including particles injected through the sample injection hole (31,131), is centrifugally separated into the particles and a fluid by rotation of the platform; and a particle collecting unit (42, 142), which is disposed at an outer end in a radial direction of the sample separation unit (40, 140), is connected to the sample separation unit(40, 140), and provides a space in which particles separated by centrifugal separation are collected; a vent channel (49, 150), which is connected to the particle collecting unit (42, 142) and of which an inner end is connected to a vent hole (151, 491) disposed to be nearer to a rotation center of the platform than the particle collecting unit (42, 142) so that a fluid of a sample can be collected by rotation of the platform; one or more outlet valves (231, 232), wherein each of the one or more outlet valves (231, 223) is connected to the sample separation unit or wherein each of the one or more outlet valves (231, 232) is connected to the vent channel (49, 150); wherein the one more outlet valves (231, 232) can be separately driven, and are disposed in a position in which a fluid having a certain volume of the separated fluid within the sample separation unit (40, 140) or the vent channel (49, 150) can be discharged by rotation of the platform; wherein the particle collecting unit(42, 142) is formed to have a depth that is greater than a depth of the sample separation unit (40, 140), and a first step portion (421, 521) that is formed at an interface between the particle collecting unit (42, 142) and the sample separation unit (40, 140). a platform, which can be rotated; a sample injection hole (31, 131), which is disposed at one side of the platform; a sample separation unit (40, 140) of which one end is connected to the sample injection hole (31, 131), and which is extended toward the outside of the platform so as to provide a space in which a sample, including particles injected through the sample injection hole (31,131), is centrifugally separated into the particles and a fluid by rotation of the platform; and a particle collecting unit (42, 142), which is disposed at an outer end in a radial direction of the sample separation unit (40, 140), is connected to the sample separation unit(40, 140), and provides a space in which particles separated by centrifugal separation are collected; a vent channel (49, 150), which is connected to the particle collecting unit (42, 142) and of which an inner end is connected to a vent hole (151, 491) disposed to be nearer to a rotation center of the platform than the particle collecting unit (42, 142) so that a fluid of a sample can be collected by rotation of the platform; one or more outlet valves (231, 232), wherein each of the one or more outlet valves (231, 223) is connected to the sample separation unit or wherein each of the one or more outlet valves (231, 232) is connected to the vent channel (49, 150); wherein the one more outlet valves (231, 232) can be separately driven, and are disposed in a position in which a fluid having a certain volume of the separated fluid within the sample separation unit (40, 140) or the vent channel (49, 150) can be discharged by rotation of the platform; wherein the particle collecting unit(42, 142) is formed to have a depth that is greater than a depth of the sample separation unit (40, 140), and a first step portion (421, 521) that is formed at an interface between the particle collecting unit (42, 142) and the sample separation unit (40, 140).