A sampling device for microscale sampling, comprising a frame, a sample container, a communicating channel, a resistance channel for causing a flow resistance all being defined in the frame, a docking plate and a tube, wherein at least one sampling chamber is defined in the communicating channel; an end of the communicating channel is communicated with the sample container and the communicating channel is arranged below the sample container; an end of the resistance channel is communicated with the sampling chamber; the other end of the resistance channel is communicated to an output joint suitable for being inserted in the tube, and the resistance channel is shaped with at least one discontinuous shape change, wherein the resistance channel is shaped with at least one discontinuous depth change, discontinuous width change or discontinuous corner; wherein a bypass channel is formed in the output joint; wherein the output joint is inserted in the tube, and the communicating channel is communicated to a first positive pressure source; the docking plate is embedded with the frame, a docking channel is defined in the docking plate; wherein the docking channel is communicated between outside environment and the bypass channel so that the tube is communicated to outside environment via the bypass channel or the docking channel is communicated between a second negative pressure source and the bypass channel so that the tube is communicated to the second negative pressure source via the bypass channel; wherein the other end of the communicating channel is communicated with a recycling chamber, the sample container is thereby communicated with the recycling chamber and a height shift is formed between the sample container and the communicating channel, the recycling chamber is configured to be able to communicate with a first negative pressure source or outside environment; and the resistance channel is arranged above the communicating channel. wherein the resistance channel is shaped with at least one discontinuous depth change, discontinuous width change or discontinuous corner; wherein a bypass channel is formed in the output joint; wherein the output joint is inserted in the tube, and the communicating channel is communicated to a first positive pressure source; the docking plate is embedded with the frame, a docking channel is defined in the docking plate; wherein the docking channel is communicated between outside environment and the bypass channel so that the tube is communicated to outside environment via the bypass channel or the docking channel is communicated between a second negative pressure source and the bypass channel so that the tube is communicated to the second negative pressure source via the bypass channel; wherein the other end of the communicating channel is communicated with a recycling chamber, the sample container is thereby communicated with the recycling chamber and a height shift is formed between the sample container and the communicating channel, the recycling chamber is configured to be able to communicate with a first negative pressure source or outside environment; and the resistance channel is arranged above the communicating channel.