Planting container unit and greening method using same

The present invention relates a container unit for greening a wall surface or the like and a greening method using the container unit, and relates to a planting container unit which is easily handled, can very easily perform even the work of greening the wall surface or the like in a short time, easily replaces plants, and has excellent maintainability. The planting container unit has: an outer container having an upper opening and a front opening; an inner container inserted into and locked by the front opening of the outer container; and a fixing plate for fixing the inner container to the outer container, wherein the inner container can accommodate a planting base such as soil and a potted plant seedling, is provided with a front opening that allows a plant part of the potted plant seedling to be exposed to the outside, and is provided with an upper opening for accommodating the planting base and the potted plant seedling separately from the front opening, the inner container has a front flange that is engaged with a wall part around the front opening of the outer container on the front surface having the front opening, and the inner container is configured to be detachably accommodated in the outer container.