A funnel is provided, including a main body and a ventilation passage. The main body is configured to lead a liquid into a receiving container. The main body includes a liquid inlet, a receiving chamber and a liquid outlet. The liquid outlet is configured to be communicated with the receiving container. The ventilation passage is configured to be communicated with the receiving container and external environment. The ventilation passage includes a first passage and a second passage which are communicated with each other. The first passage is integrally formed as a part of the main body. A first end of the first passage is configured to be communicated with the receiving container. The second passage is configured to be communicated with external environment and is detachably assembled to a second end of the first passage.