To provide an apparatus for removing a fine particle and high-concentration heavy metal ions in various kinds of waste liquids using no membrane separation device and coagulant.

A negatively charged fine particle, bacterium or fine oil in a liquid to be purified 7 is sucked on the surface of a positively charged adsorbent 2 to reciprocally coagulate the fine particle, the bacterium or the fine oil, and further positively charged metal ions in the liquid to be purified 7 are bonded with a negatively charged hydroxyl group eluted in the liquid to be purified 7 to make floc by pouring the liquid to be purified 7 in each gap of the adsorbent 2 from the upside to the downside or from downside to upside utilizing a property which elutes the negatively charged hydroxyl group in the liquid to be purified 7 by positively charging the surface of the adsorbent 2 made of a hydroxide of calcium, magnesium or aluminium when the liquid to be purified 7 has a lower pH range than a charge of 0 point, thereby removing those using no coagulant and with the filtration apparatus having a simple structure.