1. Fold the filter paper in half, twice in a row, to form a 90° central angle.

2. Fold the folded filter paper into three layers on one side and one layer on the other side to form a funnel.

3. Put the funnel-shaped filter paper into the funnel, and the edge of the filter paper should be lower than the edge of the funnel. Pour some water into the mouth of the funnel to make the soaked filter paper against the inner wall of the funnel, and then pour out the remaining water and set it aside.

4. Place the funnel with filter paper on the funnel holder for filtration (such as the ring of the iron stand), place the beaker or test tube that receives the filtrate under the funnel neck, and make the tip of the funnel neck rest on the wall of the receiving container. Prevent liquid splashes.

5. When pouring the liquid to be filtered into the funnel, hold the liquid beaker in the right hand and the glass rod in the left. The stick flows into the funnel. Note that the level of the liquid flowing into the funnel cannot exceed the level of the filter paper.

6. When the oil funnel liquid passes through the filter paper and flows down the neck of the funnel, check whether the liquid flows down the wall of the cup and pours into the bottom of the cup. If not, you should move the beaker or rotate the funnel so that the tip of the funnel is firmly attached to the wall of the beaker, so that the liquid can flow down the wall of the beaker.